RESEARCHES ON THE COAST OF SOMALIA. THE SHORE AND THE DUNE OF SAR UANLE

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1 Monitore Zoologico Italiano. Supplemento ISSN: (Print) (Online) Journal homepage: RESEARCHES ON THE COAST OF SOMALIA. THE SHORE AND THE DUNE OF SAR UANLE M. Vannini & P. Valmori To cite this article: M. Vannini & P. Valmori (1981) RESEARCHES ON THE COAST OF SOMALIA. THE SHORE AND THE DUNE OF SAR UANLE, Monitore Zoologico Italiano. Supplemento, 14:1, , DOI: / To link to this article: Published online: 12 Jul Submit your article to this journal Article views: 150 Citing articles: 4 View citing articles Full Terms & Conditions of access and use can be found at

2 Moni tore zoologico italiano ITALIAN JOURNAL OF ZOOLOGY PUBBLICATO DALLA UNIVERSITA DEGLI STUDI Dl FIRENZE CON IL CONTRIBUTO DEL CONSIGLIO NAZIONALE DELLE RICERCHE N. S. SUPPLEMENTO XIV NO. 6 : RESEARCHES ON THE COAST OF SOMALIA. THE SHORE AND THE DUNE OF SAR UANLE. 30. GRAPSIDAE (DECAPODA BRACHYURA) (PUBBLICAZIONI DEL CENTRO DI STUDIO PER LA FAUNISTICA ED ECOLOGIA TROPICALI DEL C.N.R.: CXCIII) M. VANNINI and P. VALMORI lstituto di Zoologia dell'universita di Firenze Received 28 May 1979 I. II. Introduction page 58 List of species >> 60 A. Genus Grapsus Lamarck, 1801 >> Grapsus tenuicrustatus (Herbst, 1783) >> Grapsus fourmanoiri Crosnier, 1965 >> Grapsus longitarsis Dana, 1851 >> Grapsus albolineatus Lamarck, 1818 >> 64 Remarks on the genus Grapsus >> 67 B. Genus Geograpsus Stimpson, 1858 >> Geograpsus stormi De Man, 1895 >> Geograpsus crinipes Dana, 1851 >> 68 Remarks on the genus Geograpsus >> 71 C. Genus Metopograpsus H. Milne-Edwards, 1853 >> Metopograpsus messor (Forskal, 1775) >> Metopograpsus thukuhar (Owen, 1839) >> 73 Remarks on the genus Metopograpsus >> 74 D. Genus Pachygrapsus Randall, 1840» Pachygrapsus minutus A. Milne-Edwards, 1873 >> 74 E. Genus Planes Bowdich, 1925 >> Planes cyaneus Dana, 1852» 76

3 58 M. VANNINI and P. VALMORI F. Genus Ilyograpsus Barnard, Ilyograpsus paludicola (Rathbun, 1909) G. Genus Varuna H. Milne-Edwards, V aruna litterata (Fabricius, 1798) H. Genus Utica White, Utica barbimana A. Milne-Edwards, I. Genus Pseudograpsus H. Milne-Edwards, Pseudograpsus elongatus (A. Milne-Edwards, 1873) ]. Genus Thalassograpsus Tweedie, Thalassograpsus harpax (Hilgendorf, 1892) K. Genus Nanosesarma Tweedie, Nanosesarma minutum (De Man, 1887) L. Genus Sesarma s.l. 1. Sesarma elongatum (A. Milne-Edwards, 1869) 2. Sesarma smithii H. Milne-Edwards, Sesarma meinerti De Man, Sesarma guttatum A. Milne-Edwards, Sesarma eulimene De Man, Sesarma ortmanni Crosnier, 1965 M. Genus Helice De Haan, Helice leachii Hess, 1865 N. Genus Cyclograpsus H. Milne-Edwards, Cyclograpsus integer H. Milne-Edwards, Genus Plagusia Latreille, Plagusia tuberculata Lamarck, Plagusia immaculata Lamarck, 1818 P. Genus Percnon Gistel, 1848 III. Conclusions Summary Riassunto References 1. Percnon guinotae Crosnier, Percnon planissimum (Herbst, 1804) page 77» 77» 77» 77» 79» 79» 80» 80» 82» 82» 82» 82» 83» 83» 84» 86» 87» 87» 90» 90» 90» 90» 90» 92» 92» 93» 95» 95» 97» 97» 99» 99» 99 I. INTRODUCTION During the course of eight expeditions conducted by the Centro di Studio per la Faunistica ed Ecologia Tropicali of the Consiglio Nazionale delle Ricerche, Florence (Director Prof. L. Pardi) between 1970 and 1976

4 GRAPSIDAE OF SAR UANLE 59 on the coast of Somalia (PARDI, ), about 5000 decapods were collected among which were the 354 Grapsidae listed below. While a few groups have been studied (VANNINI, 1976a, 1976b; LEWINSOHN, 1979a, 1979b) relatively little is known about the carcinological fauna of Somalia and before the above studies only a few scattered specimens had been examined by various authors (VATOVA, 1943) apart from a little collection from Hafun studied by GurNOT (1962). This paper also aims at aiding all those interested in the ecology or ethology of the intertidal crabs of this area to recognize the recorded species. The material is deposited in the Museo Zoologico of the University of Florence (MF) including nine specimens collected in Somalia prior to Some specimens are deposited in the collections of the Allan Hancock Foundation, Los Angeles (AHF), the Rijksmuseum van Natuurlijke Historie, Leiden (RMNH) and the Forschungsinstitut Senckenberg, Frankfurt a.m. (FS). A description of the Sar Uanle area and its climate is given in VAN NINI et al. (1977) and MEsSANA et al. (1977 ). All the Somalian localities mentioned in the text are shown in Fig. 30. The term «east coast of Africa» indicates the entire eastern coast of the continent while «East Africa» indicates the coast roughly corresponding to the area of the former English colonies. Synonymy is limited to those records referring to Somalia (where we have always quoted the exact locality) and to more recent or clarifying descriptions concerning the Indo-West Pacific area. SERENE & SoH (1970) substituted several new genera for the genus Sesarma but severe nomenclatural problems still exist (HOLTHUIS, 1978; TiiRKAY, personal communication) and we have used the term Sesarma s.l. Both the East African Helice and Cyclograpsus integer complex (TURKAY, personal communication) need to be revised. The identity of Nanosesarma minutum is still uncertain. We are well aware that several taxonomic problems still exist but hope that the illustrations of the animals and their pleopods will make them identifiable in the course of future revisions. The following abbreviations have been used: 1 cf plp. = first male pleopod (gonopod); 3rd mxp. = third (outer) maxilliped; abd. = abdomen. Dimensions are always in millimeters: width x length. In the text the name of the collector is omitted when the specimen has been collected by M. Vannini.

5 60 M. VANNINI and P. VALMORl We wish to thank Prof. L. B. HoLTHUIS (Rijksmuseum van Natuurlijke Historie, Leiden) for his invaluable advice since we first began this work and for the identification of various specimens, Dr M. TDRKAY (Forschungsinstitut Senckenberg, Frankfurt a.m.) for having also identified various specimens and for his critical reading of the manuscript and the friend R. INNOCENTI (technician, lstituto di Zoologia of the University of Florence), the author of the photographs. II. UST OF SPECIES FAMILY GRAPSIDAE Macleay, 1838 SUBFAMILY GRAPSINAE Macleay, 1838 A. Genus GRAPSUS Lamarck, Grapsus tenuicrustatus (Herbst, 1783) (Figs 1A, 2A, 3A, 4A). Grapsus grapsus; VATOVA, 1943 (from Merca, photo full animal). Grapsus maculatus; BARNARD, 1950 (drawings: carapace, epistome). Grapsus tenuicrustatus; HoLTHUIS, 1958, 1977; BANERJEE, 1960 (drawings: carapace, epistome, 3rd mxp., 0 abd., 1st 0 pip.; photo: full animal); CROSNIER, 1965 (drawings: 3rd mxp., 1st 0 pip.; photo: full animal). Material examined: Sar Uanle; 1 cf, 5 S? S? (3 with eggs), MF 614, October 1971; 1 cf, 1 S?, MF 616, October 1972; 3 cf cf MF 610, December Cojama Island (Bajuni Archipelago), 1 S? MF 612, leg. B. Lanza, Uarsheck, 1 cf MF 622, 1 cf FS, February Mogadiscio, 1 S? (eggs) MF 611, leg. U. Funaioli, Fuma Nangue (Bajuni Archipelago), 1 S? MF 615, October Gesira, 2 S? S? MF 613, December Morphological remarks: easily distinguished from the other Grapsus of this area by its white claw tips (HoLTHUIS, 1977) (Fig. 2). Colour: body and legs reddish-brown marbled with green. Claws external face red, tips and internal face white. Ecology: exposed rocky shores usually on cliffs. Distribution: Indo-Pacific area and from the Red Sea to Natal on the African coast. Dimensions: 64.8 x 61.5.

6 GRAPSIDAE OF SAR UANLE Grapsus fourmanoiri Crosnier, 1965 (Figs lb, 2B, 3B, 4B, 5A). Grapsus strigosus; VATOVA, 1943 (from Merca, photo: full animals); BARNARD, 1950 (drawings: epistome, 1st 0 pip.). Grapsus fourmanoiri; CROSNIER, 1965 (drawings: 3rd mxp., 1st 0 pip.; photo: full animal). Material examined: Sar Uanle, 10 cf cf, 7 <j? <j?, MF 619 and 1 cf RMNH, October 1971; 3 cfcf, 4 <j? <j? (1 with eggs), MF 620, October 1972; 2 cf cf MF 625, March 1973; 26 cf cf, 12 <j? <j? (5 with eggs), MF 617 and 1 cf, 1 <j?, AHF, December Bender Mtoni; 2 <j? <j? MF 624, October 1971; 1 <j? (eggs) MF 623, August Uarsheck, 3 cf cf, 1 <j?, MF 621, February Gesira, 3 cf cf, 1 <j?, MF 626, December Mogadiscio, 1 cf MF 627, December Morphological remarks: this species, similar to G. albolineatus has a distinguishing cf plp. (Fig. 3B ), a relatively larger front, a squarer carapace and is smaller (Fig. 1 ). Colour: as CROSNIER (1965) points out, inspite of a certain variability, the greenish yellow colour of the carapace and leg margins is very characteristic. Ecology: rocky cliffs, rocky platforms, under stones and in tidal pools on both exposed and sheltered shores. Distribution: this species, described only recently, is probably the commonest Grapsus in this area (HARTNOLL, 1975); thus, its exact distribution has yet to be defined. Dimensions: 33.4 x Grapsus longitarsis Dana, 1851 (Figs 1C, 2C, 3C, 4C, 5B) Grapsus longitarsis var. somalicus; MACCAGNO, 1930 (Somalia Italiana). Grapsus longitarsis; BANERJEE, 1960 (drawings: carapace, epistome, 3rd mxp., cheliped, dactylus of the last walking leg, 0 abd., 1st 0 pip.). Material examined: Uarsheck, 1 cf, 5 <j? <j?, MF 628, February Morphological remarks: MACCAGNO's (1930) unillustrated description of G. longitarsis somalicus is quite poor. HoLTHUIS (1958) examined the type specimens of G. longitarsis somalicus and confirmed that this was well distinct from G. granulosus H. Milne-Edwards. BANERJEE (1960) did not feel that it was a distinct variety and considered it as a synonym of G. longitarsis Dana. The only difference seen between our specimens and a pair of G. longitarsis from Tuamotu (Rijksmuseum van Natuurlijke Historie of Lei den) was that the transversal ridges of the latter are slightly more accentuated. Colour: legs yellow; carapace yellow marbled with reddish-brown; claws yellow on both faces; tips dark.

7 62 M. VANNINI and P. VALMORI Fig A, Grapsus tenuicrustatus (Herbst), o, Sar Uanle. B, G. fourmanoiri Crosnier, o, Sar Uanle. C, G. longitarsis Dana, o, Uarsheck. D, G. albolineatus Lamarck, o, Sar Uanle. E, G. granulosus H. Milne-Edwards, o, Assab (Ethiopia). Ecology: exposed rocky cliffs. Distribution: the specimens studied by MACCAGNO were collected in 1907 from a locality identified only as «Somalia Italiana». We have found it only at Uarsheck where it seems to be very common. While apparently

8 GRAPSIDAE OF SAR UANLE 63

9 64 M. VANNINI and P. VALMORI Fig Left claw (external face) of the specimens shown in Fig. 1. A, Grapsus tenuicrustatus; B, G. fourmanoiri; C, G. longitarsis; D, G. albolineatus (the claw belong to the specimen D, of Fig. 1); E, G. granulosus. absent from the rest of the western Indian Ocean, it is known in Indonesia, Formosa, Tuamotu and Hawaii. Dimensions: 32.7 x Grapsus albolineatus Lamarck, 1818 (Figs 1D,_ 3, 2D, 3D, 4D). Grapsus albolineatus; HoLTHUIS, 1958 (drawing: 1st 0 0 abd., 1st 0 pip., 1st walking leg); CROSNIER, 1965 (drawings: 1st 0 pip.), 1977; BANERJEE, 1960 (drawings: pip.; photo: full animal). Material examined: Sar Uanle; 1 d' FS, September 1971, 3 d' d' MF 631, August 1975; 3 d' d', 5 ' ' (1 with eggs), MF 635 and 1 d' AHF, December Chisimaio, 1 ' MF 634, June Mogadiscio; 1 d', 2 ' ' (1 with eggs), MF 633, leg. U. Funaioli, 1953; 1 ' MF 637, December 1~76. Gesira, 3 ' ' MF 636, December Ras Filuck, 1 d' MF 632, leg. M.L. Azzaroli, October 1973.

10 GRAPSIDAE OF SAR UANLE 65 Fig First right male pleopod of the specimens shown in Fig. 1. Upper row, outer face lower row inner face. A, Grapsus tenuicrustatus; B, G. fourmanoiri; C, G. longita;sis; D, G. dtbolineatus (the pleopod belongs to the specimen D, of Fig. 1); E, G. granulosus. Morphological remarks: while the larger specimens are easily recognized, medium and small sized animals differ from G. fourmanoiri in their more discoidal carapace (Fig. 1 ), a lower front width/height ratio (about 3:1 instead of 4: 1) (CROSNIER, 1965) and a distinguishing d' plp. (Fig. 3D) evident even in specimens which are not fully grown. In addition, the abdomen of a medium-sized female G. fourmanoiri is rounded and mature while that of a female of G. albolineatus of about the same size is still triangular and immature. Colour: body and legs reddish, marbled and mottled with brown; claws white on both faces, tips dark. Ecology: rocky shores, rocky platforms and cliffs. Apparently absent from sheltered shores.

11 66 M. VANNINI and P. VALMORI ~ \) :. I j I \ \ I I ) \ A 4 2mm 1: I \ / ' I \ \ 8 2mm c 2mm Fig The same pleopods of Fig. 3, depicted. A, Grapsus tenuicrustatus; B, G. fourmanoiri (left pleopod); C, G. longitarsis; D, G. albolineatus; ventral (left) and dorsal (right) view. Distribution: apparently absent from Madagascar (CROSNIER, 1965), Tanzania (HARTNOLL, 1975) and the entire southern coast of Africa, it is known from the Red Sea and as far as Japan and Polynesia. In Somalia this species seems quite common although less so than the preceding two species. Dimensions: 64.8 x 57.8.

12 GRAPSIDAE OF SAR UANLE 67 Fig Dactylus and propodus of the first (A,, B,) and second (A,, B,) left walking legs. A, Grapsus fourmanoiri; B, G. longitarsis. Remarks on the genus Grapsus. Of the six Indo-West Pacific species of Grapsus, G. intermedius De Man, 1888 and G. granulosus H. Milne-Edwards, 1853 are absent from Somalia. The latter is known from the Red Sea only (HoLTHurs, 1958, 1977), while G. intermedius is probably restricted to the Malay Archipelago. Records of G. intermedius from other localities have not been confirmed (HoLTHUIS, 1958, 1977; CROSNIER, 1965). Table 1 summarizes the known distribution of Grapsus on the east coast of Africa. G. tenuicrustatus Table 1. Distribution of the genus Grapsus on the east coast of Africa. N ~"0 bjl ~ 8 "3 ~ ~ ~ z --a~ ::s~ ~<ZJ... ~ Q) u :::!. ~ "' "2 ~ u ~ ~ Q) Q) ~ ~ ~ 0 ~...<:: <ZJ "0... ~... go ~~ "' 1l~ ~... <ZJ ::s 0 ~~ ~«! ~ G. fourmanoiri G. tenuicrustatus G. albolineatus + +? + G. longitarsis + G. granulosus + (1) BARNARD, 1950; (2) MACNAB & KALK, 1969; (3) CROSNIER, 1965; (4) HARTNOLL, 1975; (5) HoLTHurs, 1977.

13 68 M. VANNINI and P. VALMORI appears to be the most widespread species. G. albolineatus has not been found at Uarsheck: it might be excluded by G. longitarsis or simply not yet found. In Figs 1-3 a specimen of G. granulosus from Assab has been included for comparison. B. Genus GEOGRAPsus Stimpson, Geograpsus stormi De Man, 1895 (Figs 6A, 7A). Geograpsus lividus var. stormi; MACCAGNO, 1930 (from Somalia ltaliana). Geograpsus stormi; BARNARD, 1950 (drawing: carapace); BANERJEE, 1960 (drawings: epistome, carapace, merus of the 2nd walking leg); CROSNIER, Material examined: Sar Uanle; 1 d', 2 <:? <:?, MF 638 and 1 d' AHF, November 1971; 1 d' MF 639, October Morphological remarks: the lateral margins of the carapace are sharply keeled and diverge backwards. The upper margin of the buccal cavity is (l) -shaped and denticulated. Colour: carapace dark red (sometimes nearly black), legs bright red with practically no variability. Ecology: inside holes in the cliff, a little above HWS. Seldom seen wandering on the cliff, it usually stays very near its hole and never stays on to the rocky platform or into the bush behind the cliff. Very common where the cliff is riddled. Distribution: from the east coast of Africa to Japan, Polynesia and Hawaii. Absent from the Red Sea and rare in Madagascar and South Africa. Dimensions: 32.1 x Geograpsus crinipes Dana, 1851 (Figs 6B, 7B). Geograpsus crinipes; BANERJEE, 1960 (drawings: carapace, epistome, cheliped, sternite of the cheliped, 1st O pip.); HOLTHUIS, Material examined: Sar Uanle, 1 <:? MF 640, August Morphological remarks: the lateral margins are keeled and diverge slightly backwards. The upper margin of the buccal cavity is straight. Colour: an almost uniform yellow. Ecology: the specimen was collected on the sea edge of the rocky platform during low tide, a little above LWST. It is known to be semiterrestrial and can wander quite far inland.

14 GRAPSIDAE OF SAR UANLE 69 Fig A, Geograpsus stormi De Man, o, Sar Uanle. B, G. crinipes Dana, o, Samoa (Polynesia). C, G. grayi (H. Milne-Edwards), o, Maldive.

15 70 M. VANNINI and P. VALMORI Fig First right male pleopod of the specimens shown in Fig. 6. Upper row, outer face; lower row, inner face. A. Geograpsus stormi; B, G. crinipes; C, G. grayi.

16 GRAPSIDAE OF SAR UANLE 71 Distribution: from the Red Sea to Japan and Hawaii. Absent in Madagascar and never recorded before on the coast of East Africa, it has been found on various small islands of the western Indian Ocean (HARTNOLL, 1975). Dimensions: 35.5 x Remarks on the genus Geograpsus. The third West-Indo Pacific species, Geograpsus grayi (H. Milne Edwards, 1953 ), is absent from Somalia and all the African coast, though quoted in the Red Sea it has not been found by either NoBILl (1906) or HoLTHUIS (1958, 1977). It seems very common in Madagascar and all the Indian Ocean islands. It differs from the other two in the lateral margins which clearly converge backwards, in the obtuse, unkeeled postero-lateral margin and in its distinguishing 1st cf plp. (Figs 6C, 7C). The commonest species from Somalia to Natal is Geograpsus stormi and from the Red Sea, Geograpsus crinipes. C. Genus METOPOGRAPSUS H. Milne-Edwards, Metopograpsus messor (Forskal, 1775) (Figs 8A, 9A). Metopograpsus messor; BARNARD, 1950 (drawings: orbit, carapace, 1st 0 pip.); HOLTHUIS, 1958, 1977; BANERJEE, 1960 (drawings: 0 abd., ' sternum, carapace); GurNor, 1962 (from Hafun); CROSNIER, 1965 (drawings: orbit, 1st 0 pip., reproduced from FoREST & GUFNOT, 1961). Material examined: Sar Uanle, 1 cf MF 645, June Lac Badana, 4 cf cf, 6 <:? <:;?, MF 643 and 1 cf FS, November Gesira, 1 <:;? MF 646, August Bender Mtoni, 1 cf MF 644, August Abo, 3 cf cf, 1 <:?, MF 654, leg. M.L. Azzaroli, October Morphological remarks: the lateral margins clearly converge backwards and there is only a small chitinous projection on the tips of the stout cf plp. Colour: carapace and legs brownish green and irregularly mottled. Claws brownish red on both faces with clearer tips. Ecology: in Somalia it is usually found under rotten wood or dead masses of Saccostrea in muddy flats near or in mangroves. Distribution: Red Sea, Persian Gulf, east coast of Africa, Madagascar. Dimensions: 22.1 x 17.5.

17 72 M. VANNINI and P. VALMORI Fig A, Metopograpsus messor (Forskill), o, Lac Badana. B, M. thukuhar (Owen), o, Gesira. C, M. oceanicus (Jacquinot), o, Kenya.

18 GRAPSIDAE OF SAR UANLE 73 A c I 1/ r} _.- ; ~ ):. --,i;. ~ <. ~.. ;... -~-- : 1 mm \. B 1 mm I \ 1 mm Fig First right male pleopod of the specimens shown in Fig. 8. A, Metopograpsus messor; B, M. thukuhar; C, M. oceanicus; ventral (left) and dorsal (right) view. 2. Metopograpsus thukuhar (Owen, 1839) (Figs 8B, 9B). Metopograpsus thukuhar; BANERJEE, 1960 (drawings: propodus of the 5th walking leg, 0 sternum); CROSNIER, 1965 (drawings: carapace, 3rd mxp., orbit, 1st 0 pip., reproduced from FOREST & GUINOT, 1961); HOLTHUIS, Material examined: Sar Uanle, 1 cf MF 650, October Bender Mtoni; 1 cf MF 649, October 1971; 7 cf cf, 9!;;?!;;?, MF 648 and 2 cf cf, 2!;;?!;;?, AHF and 1 cf FS, December Lac Badana, 1 cf MF 653, October Gesira; 1 cf MF 652, February 1972; 9 cf cf, 6!;;?!;;?, MF 647, December Abo, 1 cf MF 651, leg. M.L. Azzaroli, October Morphological remarks: the tip of the cf plp. has a distinguishing chitinous projection. The internal orbital tooth varies considerably and

19 74 M. VANNINI and P. VALMORI does not allow for the easy distinction which CROSNIER's (1965, figs 26, 27) picture would lead one to believe. Colour: carapace and legs brownish-yellow or brownish red, variably mottled. External face of the claw violet (pink among juveniles). Ecology: mainly in mangroves. Distribution: Japan, Tahiti and Hawaii. From Red Sea to South Africa on the African coast. Dimensions: 26.1 x Remarks on the genus Metopograpsus. Metopograpsus oceanicus (Jacquinot, 1852) known from Kenya and Tanzania, seems missing in Somalia. Distinguished by a tooth behind the external orbital one (Fig. 8C) it apparently inhabits coastal mangroves in Tanzania together with Metopograpsus messor while Metopograpsus thukuhar is more common in mangrove creek (HARTNOLL, 1975). While there are no coastal mangrove in Somalia, there are mangrove creeks where M. messor may well occur, M. oceanicus, instead, is probably excluded. No Metopograpsus have been found in the mangrove at the mouth of the Giuba River. D. Genus PACHYGRAPSUS Randall, Pachygrapsus minutus A. Milne-Edwards 1873 (Figs loa, lla). Pachygrapsus minutus; CROSNIER, 1965 (drawings: carapace, 1st 0 pip., orbit}; HoLTHUIS, Material examined: Sar Uanle; 1 d', 3 <j? <j?, MF 656, October 1971; 1 d', 2 <j? <i?, MF 660, November 1972,2 d'd', 2 <j? <i?, MF 655, March 1973; 6 d'd', 6 <j? <j? (1 with eggs), MF 658, July 1975; 15 d'd', 17 <j? <i? (9 with eggs), MF 661 and 1 d' FS, December Bender Mtoni; 1 d' MF 659, October 1971; 1 d', 1 <j?, MF 673, December Lac Badana, 1 <j? MF 657, October Gesira, 3 d' d', 4 <j? <j? (1 with eggs), MF 672, December Morphological remarks: the lateral margins of the carapace have a single tooth (Fig. loa), the glabrous transversal ridges on the carapace and aspect of the 1st d' plp. (Fig. lla) are typical (CROSNIER, 1965). Colour: light brownish-yellow, mottled. Ecology: very common on the lowest part of the cliff and on the rocky platform where it shows a zonation similar to that of Grapsus

20 GRAPSIDAE OF SAR UANLE 75 Fig A, Pachygrapsus minutus A. Milne-Edwards, o, Sar Uanle. B, Planes cyaneus Dana, o, Sar Uanle. C, Ilyograpsus paludicola (Rathbun), ~, Abo. 10

21 76 M. V ANNINI and P. V ALMORI fourmanoiri. On the cliff it finds shelter in any kind of crevice including empty barnacles. It has often been observed grazing among the spines of the mantle of large chiton (Acanthopleura sp.). Occasionally found under stones or Saccostrea masses on sheltered beaches or in mangroves. Distribution: Red Sea, East Africa, Madagascar and as far as Japan, Hawaii and Polynesia. Dimensions: 6.2 x 4.5 \ A \ \. j ' j l I '( I \ l 0.5 mm \ I i! I /}' / i ' B? s ('~ \ I ('\ ; ~ 1 mm Fig First right male pleopod. A, Pachygrapsus minutus (the specimen shown in Fig. 10); B, Planes cyaneus (a specimen 13.7 mm width); ventral (left) and dorsal (right) view. ~ E. Genus PLANES Bowdich, Planes cyaneus Dana, 1852 (Figs lob, llb). Planes cyaneus; CHACE, 1951 (drawings: full animal, 0 claw, 2nd walking leg, 0 c pip.); CROSNIER, 1965 (drawings: carapace). Planes minutus; VANNINI, 1976b. abd., 1st Material examined: Sar Uanle, 2 cf cf MF 662, July Mogadiscio, 1 c;? (with eggs) MF 663, leg. U. Funaioli, Morphological remarks: the claws, walking legs, carapace shape and 1st cf plp. are all elements that would, according to CHACE ( 1951 ), identify our specimens as Planes cyaneus. However the cf abd. alone is that of Planes minutus (1., 1758). In addition, it seems to be ever more apparent that P. minutus is restricted to the Atlantic Ocean (CHACE, 1951; CROSNIER, 1965; HOLTHUIS, 1977). Colour: blue.

22 GRAPSIDAE OF SAR UANLE 77 Ecology: these specimens were found on sandy beaches in a period when many Janthina sp. (Gastropoda) were also stranded. CHACE (1951) quoted that P. minutus might also be found on Janthina. Both P. cyaneus and Janthina were quite common in August 1975 and absent in February March (1973 ), May-June (1973 ), September-October ( 1972), October November (1971) and December (197 6 ). Distribution: Indo-Pacific; apparently unknown previously on the east coast of Afri::a. Dimensions: 14.5 x F. Genus ILYOGRAPSUS Barnard, Ilyograpsus paludicola (Rathbun, 1909) (Fig. 10C). Jlyograpsus rhizophorae; BARNARD, 1955 (drawings: carapace, C abd., 1st c pip., c claw. 3rd mxp.). Jlyograpsus paludicola; CROSNIER, 1965 (drawings: carapace, 3rd mxp., orbital region, c ab:l.); HOLTHUIS, Material examined: Abo, 2 c;? c;? (with eggs) MF 664, leg. M.L. Azzaroli, October Morphological remarks: these specimens correspond well to the description by BARNARD (1955), CROSNIER (1965) and HOLTHUIS (1977). It is the only species belonging to this genus. Colour: carapace a uniform pale yellow, legs mottled. Ecology: mangroves. Distribution: Thailand and from Red Sea to Natal, on the African coast. Dimensions: 4.4 x 4.0. SunFAMILY VARUNINAE Alcock, 1900 G. Genus VARUNA H. Milne-Edwards, Varuna litterata (Fabricius, 1798) (Figs 12A, 13A). Varuna litterata; BARNARD, 1950 (drawings: orbital region, carapace, 1st 0 pip.); CROSNIER, 1965 (drawings: 3rd mxp., 1st 0 pip.; photo: full animal). Material examined: Ola Dager; 6 cf cf, 1 c;?, MF 665, leg. A.M. Simonetta, July 1959; 5 cf cf, 4 c;? c;?, MF 666, July Morphological remarks: carapace glabrous, flattened.

23 78 M. VANNINI and P. VALMORI Fig A, Varuna litterata (Fabricius), o, Ola Uager. B, Utica barbimana A. Milne-Edwards, o, Gesira. Colour: reddish brown, last three segments of the walking legs with long black hairy fringes. Ecology: found only in small pools at Ola Uager. The pools are connected 2-3 weeks/year to the sea by a stream during the rainy season(s). Other pools were inhabited by Potamon obesus bottegoi (De Man) or Macrobrachium rudis (Heller). V aruna litterata can tolerate high salinity levels such as in False Bay on the St. Lucia River (52.6 %o) (DAY et al., 1953). FouRMANOIR (1954) also found it on floating wood.

24 GRAPSIDAE OF SAR UANLE 79 Distribution: apparently absent from the Red Sea, it is widespread along the African coast as far as Natal, and over the entire Indian Ocean as far as Japan and Australia. Dimensions: 40.9 x A B ' \:.1 ' l I! ; I. I.I '( >l \ I I "' ' '- I!. / E E ~- \ 'J Fig First right male pleopod of the specimens shown in Fig. 12. A, Varuna litterata; B, Utica barbimana; ventral (left) and dorsal (right) view. H. Genus UTICA White, Utica barbimana A. Milne-Edwards, 1873 (Figs 12B, 13B, 14A-D). Utica barbimana; HoLTHUIS, 1977 (drawings: 0 and? carapace, 1st 0 pip.). Material examined: Gesira, 1 d' MF 667, December Morphological remarks: carapace hairy, flattened, two teeth behind the external orbital one. It has recently been carefully re-described by HoLTHurs (1977). Colour: uniform violaceous brown. Ecology: mangrove, under a dead trunk half-buried in the mud. It has also been recorded from fresh water (New Caledonia).

25 80 M. VANNINI and P. VALMORI \.!I ~ ~ '--~---"' / '\~ )' -, \{ \ D Fig Utica barbimana, specimen of Fig. 12. A, carapace; B, abdomen; C, 3rd maxi!liped; D, dactylus and propodus of the 4th and 5th right walking legs. Distribution: Red Sea, New Caledonia. Dimensions: 9.0 x 8.8. I. Genus PsEUDOGRAPsus H. Milne-Edwards, Pseudograpsus elongatus (A. Milne-Edwards, 1873) (Fig. 15A, B). Pseudograpsus erythraeus; BARNARD, 1950; HOLTHUIS, Pseudograpsus elongatus; CROSNI;ER, 1965 (drawings: carapace, 3rd mxp., 0 abd., 4th walkiug leg); HOLTHUIS, Material examined: Bender Mtoni, 1 cf, 1 9 (with eggs), MF 668, December 1976.

26 GRAPSIDAE OF SAR UANLE 81 Fig Pseudograpsus elongatus (A. Milne-Edwards); A, o; B, 9; Bender Mtoni. C, Thalassograpsus harpax (Hilgendorf), 9, Bender Mtoni.

27 82 M. VANNINI and P. VALMORI Morphological remarks: the obvious lateral teeth, the posteriorly convergent lateral margins and the typical cf plp., easily distinguish this species from Pseudograpsus albus Stimpson, the only other member of this genus known in the Indo-West Pacific area. Colour: carapace and claws brownish-yellow; legs pale yellow, dactylus and distal half of the propodus even paler. Ecology: under a block of dead Crassostrea on a muddy sheltered beach. Distribution: from the Red Sea to Natal, Madagascar, Seychelles and New Caledonia. Dimensions: 6.4 x 5.9. }. Genus THALASSOGRAPSUS Tweedie, Thalassograpsus harpax (Hilgendorf, 1892) (Fig. 15C). Tlwlassograpsus harpax; TWEEDIE, 1950 (drawings: fronto-orbita} region, claws); SERE~E & UMALI, 1972 (drawings: 1st C pip.; photo: full animal); HoLTHUIS, Material examined: Bender Mtoni, 1 9 (with eggs) MF 669, October Morphological remarks: our specimen correspond to the description of TwEEDIE (1950) and SERENE & UMALI (1972). It is the only species belonging to this genus. Colour: carapace greenish brown, legs lighter. Ecology: in mangroves. Distribution: Gulf of Aden, Somalia, Tanzania, Japan, Malaysia, Polynesia. Dimensions: 5.0 x 4.5. SuBFAMILY SESARMINAE Dana, 1852 K. Genus NANOSESARMA Tweedie, Nanosesarma minutum (De Man, 1887) (Fig. 16). Nanosesarma cfr. minutwn; CROS~IER, 1965 (drawings: 1st cj pip., carapace, 3rd mxp., claw, merus of the 2nd and 4th walking leg, C abd.; photo: full animal). Material examined: Bender Mtoni, 2 cf cf, (3 with eggs), MF 671 and 1 cf, 1 9, AHF, December Gesira, 1 cf MF 670, December 1976.

28 GRAPSIDAE OF SAR UANLE 83 Morphological remarks: HoLTHUIS (1977) suggests that the specimens from Madagascar which CROSNIER ( 1965) identified as Nanosesarma cfr. minutum might be Nanosesarma jousseaumei Nobili. Our specimens agree with both descriptions. Colour: a uniform dirty grey. Fig Nanosesarma minutum (De Man), o, Sar Uanle. Ecology: common on rotten wood half buried in the mud, in mangroves. Distribution: Thailand, Java. Dimensions: 5.6 x 4.8. from Somalia to Tanzania, Madagascar, Singapore, L. Genus SESARMA s. I. (see Introduction) 1. Sesarma elongatum (A. Milne-Edwards, 1869) (Figs 17 A, 18A). Sesarma (Holometopus) elongatum; CROSNIER, 1965 (drawings: 1st 0 pip., claw, 0 mxp.; photo: full animal). abd., 3rd Material examined: Sar Uanle, 1 ~ MF 675, June Bender Mtoni, 1 cf, 1 ~, MF 674, December 1976.

29 84 M. VANNINI and P. VALMORI Morphological remarks: lateral margins entire; upper face of the claw propodus with a longitudinal keeled ridge; merus of the walking legs broad (length twice the width or slightly less). Colour: carapace brownish-violet; external claw lighter; legs mottled. Fig A, Sesarma elongatum A. Milne-Edwards,.), Bender Mtoni. B, S. smithii H. Milne-Edwards, c!, Giumbo. C, S. meinerti De Man, c!, Giumbo. D, S. guttatum A. Milne-Edwards, 0, Giumbo. E, Helice leachii H. Milne-Edwards, <j, Giumbo. Ecology: the Sar Uanle specimen was found on a floating palm tree, while those from Bender Mtoni were collected (and others were seen) on the trunks of mangrove trees, usually near the base. Distribution: Somalia, Tanzania, Madagascar, Andamane, Indonesia. Dimensions: 27.8 x Sesarma smithii H. Milne-Edwards, 1853 (Figs 17B, 18B, 19A). Sesarma (Sesarma) smithii; BARNARD, 1950; CROSNIER, 1965 (drawing: claw, 1st 0 pip., 0 abd.; photo: full animal). Material examined: Giumbo, 2 rj rj MF 676, December 1976.

30 GRAPSIDAE OF SAR UANLE R5 A B I / 1 mm./ I II I " "" I " ; ' I 1 mm ~.. 0 If;.,, ~ ' i I I 'II j -~ I I D c ); ---: 1 mm --~ 2mm :;~ Fig First right male pleopod of the specimens of Fig. 17. A, Sesarma elongatum; B, S. smithii; C, S. meinerti; D, S. guttatum; ventral (left) and dorsal (right) view.

31 86 M. VANNINI and P. VALMORI Morphological remarks: carapace squarish, lateral margins with two obvious teeth (besides the external orbital one); upper face of the claw propodus with two longitudinal ridges, dactylus with two stout spines near the base (less obvious in females). Fig Right chela (external face) of the specimens of Fig. 17. A, Sesarma meinerti; B, S. smithii; C,,, S. guttatum. Colour: carapace and legs dark violet; claw propodus mostly red on both faces (dark violet at the base), white tips. Ecology: the specimens were found under a dead trunk in the mangrove swamp of Giumbo in the Giuba River estuary. Distribution: from Somalia to Natal, Madagascar, Australia, New Caledonia and Japan. Dimensions: 26.9 x Sesarma meinerti De Man, 1887 (Figs 17C, 18C, 19B). Sesarma (Sesarma) meinerti; VATOVA, 1943 (from Giumbo; photo: full animal); BARNARD, 1950 (drawings: claw, 1st 0 pip.); CROSNIER, 1965 (drawings: 0 abd., carapace, frontal region, claw, 1st o pip.). Material examined: banks of the Giuba River (3 km from the mouth), 1 cf MF 677, December Giumbo, 2 cfcf, 3 <lj <l> (1 with eggs), MF 678, December Morphological remarks: lateral margins converging backwards, with a single tooth (besides the external orbital one); upper face of the claw propodus with rows of granules, dactylus with at least seven small spines.

32 GRAPSIDAE OF SAR UANLE 87 Colour: carapace dark violet, anterior and beginning of the lateral margins red; eyestalks red; claw base red, fingers pale yellow. Ecology: together with the preceding species in the Giumbo mangrove and very common along the banks of the Giuba River from where Sesarma smithii is absent. Muddy areas bordering the river are riddled with the burrows of this species and those of Cardisoma carnifex (Herbst). Distribution: from Somalia to Natal, Madagascar, Australia. Dimensions: 42.9 x Sesarma guttatum A. Milne-Edwards 1869 (Figs 17D, 18D, 19C_z). Sesarma (Chiromantes) guttata; BARNARD,!950 (drawings: claw, 1st?: pip.). Sesarma (Chiromantes) guttatus; CROSNIER, 1965 (drawings: claw, ca~apace, 1st 0 pip.). Sesarma (Perisesarma) gut tatum; HoLTHurs, Material examined: Bender Mtoni, 3 cf cf MF 696, October Abo, 2 <;? <;? (1 with eggs) MF 695, leg. M.L. Azzaroli, October Durbo, 1 cf, 1 <;?, MF 697, leg. M.L. Azzaroli, October Giumbo, 6 cf cf, 4 <;? <;?, MF 679 and 1 cf AHF, December Morphological remarks: carapace squarish with a single tooth (besides the external orbital one); upper face of the claw propodus with two pectinate transversal ridges, dactylus with a row of 11 or more chiton-like tubercules. Colour: carapace dark violet, walking legs pale violet; claw: external side violet on the upper face and near the base, remainder (tips included) red, internal side bright red-orange. Ecology: in mangroves. Distribution: Red Sea, Somalia, Tanzania, Madagascar. Dimensions: 26.8 x Sesarma eulimene De Man, 1898 (Figs 20A, 21Al-z, 22A). Sesarma (Holometopus) eulimene; BARNARD, 1950 (drawings: claw, 1st c pip.); CROSNIER, 1965 (drawings: 0 abd., carapace, claw, merus of the 4th walking leg, 1st c pip.). Material examined: Giumbo, 12 cf cf, 13 <;? <;?, MF 681 and 1 cf FS, December Banks of the Giuba River (3 km from the mouth), 7 cf cf, 1 <;?, MF 682, December Morphological remarks: anterior margin of the merus of the walking legs with a subdistal spine. It can be distinguished from the following species by the shape and aspect of the tubercules on the claw dactylus.

33 88 M. VANNINI and P. VALMORI Fig A, Sesarma eulimene De Man, o, Giumbo. B, S. ortmanni Crosnier, o, Giumbo. Colour: carapace yellowish-brown; claws pale yellow-orange, dactylus whitish. Immobile finger whitish at tip. Ecology: similar to Sesarma meinerti. On river banks Sesarma eulimene is found near to or on the water line. Distribution: Somalia, Tanzania, South Africa, Madagascar. Dimensions: 24.2 x 21.4.

34 GRAPSIDAE OF SAR UANLE 89 Fig Right chela of the specimens of Fig. 20 (external and upper faces). A 1, 2, Sesarma eulimene; B,,,, S. ortmanni. B Fig mm First right male pleopod of the specimens of Fig. 20. A, Sesarma eulimene; B, S. ortmanni; ventral (left) and dorsal (right) view. /

35 90 M. VANNINI and P. VALMORI 6. Sesarma ortmanni Crosnier, 1965 (Figs 20B, 21Bt-2, 22B). Sesarma erythrodacty/a var. africana; VATOVA, 1943 (from Giumbo); CROSNIER, 1965 (drawings: claw, carapace). Material examined: Gesira, 2 d d, 2 9 9, MF 698, February Giumbo, 2 d d, 5 9 9, MF 684 and 1 d FS, December Morphological remarks: the claw dactylus clearly differs from that of the preceding species only in adult males. Moreover, Sesarma ortmanni is generally lighter and smaller than Sesarma eulimene and has the immobile finger of the claw whitish not just at the tip but for about half of its length. Colour: carapace brownish yellow; claws yellow, mobile (dactylus) and immobile fingers whitish distally. Ecology: in mangroves. Distribution: Somalia, Tanzania, Madagascar. Dimensions: 15.9 x M. Genus HELICE DeHaan, Helice leachii Hess, 1865 (Fig. 17E). Helice leachii; HOLTHUIS, 1958, 1977; CROSNIER, 1965 (drawings: orbital region, 3rd mxp., c abd., 1st c pip.; photo: full animal). Material examined: Giumbo, 1 9 MF 686, December Morphological remarks: pterygostomial region without reticulate hairy rows; carapace convex, lateral margins with two teeth (besides the external orbital one); body remarkably thick. Colour: carapace dark brown, legs and claws lighter brown. Ecology: in mangroves. Distribution: Red Sea, Somalia, Tanzania, Madagascar, Australia, New Caledonia, Formosa, Japan. Dimensions: 15.6 x N. Genus CYCLOGRAPSUS H. Milne-Edwards, Cyclograpsus integer H. Milne-Edwards, 1837 (Figs 23A, B; 24). Cvc/ograpsus illleger; FOREST & GUINOT, 1961 (drawing: 1st,-' pip.); CROSNIER, 1965 (drawing: c~rapacc); GRIFFIN, 1968 (drawings: claw, propodus and dactyl.;s of the 4th walking leg, 0 abd.).

36 GRAPSIDAE OF SAR UANLE 91 Fig Cyclograpsus integer H. Milne-Edwards; A, o; B, ' ; Sar Uanle. Material examined: Sar Uanle, 1 r:f, 1 <j?, MF 687, December Morphological remarks: pterygostomial region without reticulate hairy rows; carapace anteriorly convex; lateral margins entire. Colour: violaceous brown, uniform. 11

37 92 M. VANNINI and P. VALMORI Ecology: in little crevices on the cliff of semi-sheltered shores; above HWST, almost the same habitat as Lydia annulipes (H. Milne-Edwards) (Xanthidae). Common but difficult to see and catch. Distribution: a circumtropical crab, apparently absent only from Hawaii and the western coast of America. In the Indo-West Pacific known only from Madagascar; unrecorded by HARTNOLL (1975) in Tanzania. Dimensions: 15.6 x \ Fig First male pleopod of the specimen of Fig. 23; Cyclograpsus integer; ventral (left) and dorsal (right) view. SuBFAMILY PLAGUSIINAE Dana, Genus PLAGUSIA Latreille, Plagusia tuberculata Lamarck, 1818 (Figs 25A, 26A, 27A). Plagusia depressa tuberculata; BARNARD, 1950; CROSNIER, 1965 (photo: carapace). Plagusia tuberculata; VANNINI, 1976b; HOLTHUIS, Material examined: Sar Uanle; 1 d', 1 c;;? (with eggs) MF 688, October 1971; 1 d', 1 c;;? (with eggs), MF 681, November 1972; 1 c;;? MF 689, June 1973; 3 d' d', 2 c;;? c;;?, MF 690, July Morphological remarks: tubercules of the carapace hairy. Colour: light brown, mottled. Ecology: under stones or in crevices on the rocky platform, far from the cliff. Said to be common on floating wreckage. Distribution: Australia, Hawaii. Dimensions: 38.8 x from the Red Sea to Natal, Madagascar, Japan,

38 GRAPSIDAE OF SAR UANLE 93 Fig A, Plagusia tuberculata Lamarck, o, Sar Uanle. B, P. immaculata Lamarck, o, Sar Uanle. 2. Plagusia immaculata Lamarck, 1818 (Figs 25B, 26B, 27B). Plagusia immaculata; CROSNIER, 1965 (photo: full animal). Material examined: Sar Uanle; 1 cf MF 693, October 1971; 1 cf MF 694, June Morphological remarks: carapace glabrous. 11*

39 94 M. VANNINI and P. VALMORI Fig Enlargement of carapace. A, Plagusia tuberculata; B, P. immaculata.

40 GRAPSIDAE OF SAR UANLE 95 Colour: as in the preceding species. Ecology: as in the preceding species. Distribution: Somalia, Ta.1zania, Madagascar and as far as Japan, Hawaii and the west coast of America (Costa Rica). Dimensions: 31.1 x A B 1 mm E E Fig First right male pleopod of the specimens of Fig. 25. A, Plagusia tuberculata; B, P. immaculata; ventral (left) and dorsal (right) view. P. Genus PERCNON Gistel, Percnon guinotae Crosnier, 1965 (Figs 28A, 29). Percnon guinotae; CROSNIER, 1965 (drawings: carapace, epistome, claw, 0 1st 0 pip.; photo: full animal). abd., 3rd mxp., Material examined: Sar Uanle; 3 cf cf, 1 ~, MF 695 and 1 ~ AHF, October 1971; 1 cf MF 696, August Gesira, 1 ~ MF 697, December Morphological remarks: epistome with a single spine; claw propodus with a hairy groove on the upper face and a little hairy area near the base, on the internal face. Colour: light brown streaked with blue and green.

41 96 M. V ANNINI and P. V ALMORI Fig A, Percnon guinotae Crosnier,, Sar Uanle. B, C. planissimum (Herbst),, Sar Uanle. Ecology: under stones or in crevices on the rocky platform (usually far from the cliff) and on the reef where it is the only Grapsidae ever found. Distribution: Oceania. Dimensions: 22.1 x Somalia, Tanzania, Madagascar, Aldabra, Moluques,

42 GRAPSIDAE OF SAR UANLE Percnon planissimum (Herbst, 1804) (Fig. 28B ). Percnon planissimwn; BARNARD, 1950 (drawings: claw, 1st 0 claw, 1st O pip.); HOLTHUIS, pip.); CROSNIER, 1965 (drawings: Material examined: Sar Uanle, 1 9 MF 698, August Morphological remarks: the only East African Percnon without any trace of a hairy groove on the upper face of the claw propodus. Colour: light brown with paler brown streaks. Ecology: in crevices on the rocky platform, far from the cliff. Fig Percnon guinotae, Sar Uanle, first right male pleopod; ventral (left) and dorsal (right) view. 1 mm. : :.....'\1. Distribution: from the Red Sea to South Africa, Madagascar and as far as Japan and Hawaii. Though uncommon at Sar Uanle, it is as frequent as the previous species in Tanzania (HARTNOLL, 1975) and the commonest one in Madagascar (CROSNIER, 1965). Dimensions: 16.2 x III. CONCLUSIONS Our study has been concentrated on the sandy beach, cliff and rocky intertidal platform of the exposed beach at Sar Uanle and less attention has been given to sheltered beaches, mangroves, estuaries and reefs. No study was been made of the infra-littoral. Both the discovery of Grapsus albolineatus (whose presence on the East African coast was in qaestion; CROSNIER, 1965; HARTNOLL, 1975) and rediscovery of Grapsus longitarsis are of interest. Cyclograpsus integer has not previously been recorded on the continental coast. HARTNOLL ( 1975), in spite of his undoubtedly excellent

43 98 M. VANNINI and P. VALMORI so 8 o rr oem Durbo 2 Abo 3 Ras Filuck 4 Hafun s Uarsheck 6 Mogadiscio 7 Gesira 8 Me rca 9 Giumbo 10 Bender Mtoni 11 Sar Uanle 12 Bajuni 13 Lac Badana 14 Ola Uager Fig Map showing the Somalian localities mentioned in the text

44 GRAPSIDAE OF SAR UANLE 99 study of the Tanzania coast did not find this species while, it appears to be quite common on the upper half of the cliff at Sar Uanle. Planes cyaneus is also recorded for the first time on the East African coast. We found a total of 28 species of Grapsidae (of which only seven had been previously recorded in Somalia; VATOVA, 1943), HARTNOLL's (1975) list of Grapsidae from the East African area can now include Grapsus albolineatus, Geograpsus crinipes, Planes cyaneus, Cyclograpsus integer and, if we wish to include Uarsheck (2 18'N) in this area, Grapsus longitarsis, making a total of 40 Grapsidae known at present from this area. Our ecological observations fully agree with HARTNOLL's findings in Tanzania. SUMMARY A collection of crabs mostly from Sar Uanle and neighbouring zones (southern Somalia) contained 28 species of Grapsidae (Decapoda Brachyura), of which only seven had been previously recorded in Somalia. Four species are new for the east coast of Africa. RIASSUNTO Da una collezione di Granchi provenienti da varie localita somale e soprattutto da Sar Uanle (Somalia meridionale) sono state identificate 28 specie di Grapsidi (Decapoda Brachyura) di cui 21 nuovi per la Somalia e 4 nuovi per la costa dell'africa orientale. REFERENCES BANERJEE, S. K Biological results of the Snellius Expedition. XVIII. The genera Grapsus, Geograpsus and Metopograpsus (Crustacea Brachyura). Temnickia 10: BARNARD, K. H Descriptive catalogue of South African decapod Crustacea. Ann. S. Afr. Mus. 38: BARNARD, K. H Additions to the fauna-list of South African Crustacea and Pycnogonida. Ann. S. Afr. Mus. 43 (1): CHACE, F. A., JR The oceanic crabs of the genera Planes and Pachygrapsus. Proc. U. S. natn. Mus. 101: CROSNIER, A Crustaces Decapodes. Grapsidae et Ocypodidae. Faune de Madagascar 18: DAY,]. H., N. A. H. MILLARD & G. J. BROEKHUYSEN African estuaries. Part IV: the St. Lucia system The ecology of South Trans. R. Soc. S. Afr. 34:

45 100 M. VANNINI and P. VALMORI FoREST, J. & D. GurNOT Crustaces Decapodes Brachyoures de Tahiti et des Tuamotu. In: Expedition fran~aise sur les recifs coralliens de la Nouvelle Caledonie. Volume preliminaire. Paris: Ed. Foundation Singer-Polignac, XI+195 pp., 17 pls. FoURMANOIR, P Crabes de la cote Ouest de Madagascar. Naturaliste malgache 6: GRIFFIN, D. J. G A new species of Cyclograpsus (Decapoda Grapsidae) and notes on five others from the Pacific Ocean. Crustaceana 15 (3 ): GurNOT, D Sur une collection de Crustaces Decapodes Brachyoures de Mer Rouge et de Somalie. Remarques sur les genres Calappa Weber, Menaethiops Alcock, Tyche Bell, Ophthalmias Rathbun et Stilbognathus von Martens. Boll. Mus. civ. Stor. nat. Venezia 15: HARTNOLL, R. C The Grapsidae and Ocypodidae (Decapoda: Brachyura) of Tanzania. J. Zool., Land. 177: HoLTHUIS, L. B Contributions to the knowledge of the Red Sea. No. 9. Crustacea Decapoda from the northern Red Sea (Gulf of Aqaba and Sinai Peninsula). II. Hippidea and Brachyura (Dromiacea, Oxystomata and Grapsidea). Bull. Sea Fish. Res. Stn Israel No. 17: HoLTHUIS, L. B The Grapsidae, Gecarcinidae and Palicidae (Crustacea: Decapoda: Brachyura) of the Red Sea. Israel J. Zool. 26: HoLTHUIS, L. B A collection of decapod Crustacea from Sumba, lesser Sunda islands, Indonesia. Zool. Verh., Leiden No. 162: LEWINSOHN, CH. 1979a. Researches on the coast of Somalia. The shore and the dune of Sar Uanle. 21. Dromiidae (Crustacea Decapoda Brachyura). Monitore zool. ital. (N. S.) Suppl. 12: LEWINSOHN, CH. 1979b. Researches on the coast of Somalia. The shore and the dune of Sar Uanle. 23. Porcellanidae (Crustacea Decapoda Anomura). Monitore zool. ital. (N. S.) Suppl. 12: MACCAGNO, T Crostacei Decapodi: due Grapsidae della Somalia Italiana. Boll. Musei Zool. Anat. comp. R. Univ. Torino 41 (No. 15): MACNAE, W. & M. KALK A natural history of Inhaca Island, Mo~ambique. Johannesburg: Witwatersrand University Press, V pp. MESSANA, G., G. CHELAZZI, L. CHELAZZI, A. ERCOLINI, F. FERRARA, P. MESSER!, L. PARDI & M. VANNINI Researches on the coast of Somalia. The shore and the dune of Sar Uanle. 12. Physical environment: microclimate and soil. Monitore zool. ital. (N. S.) Suppl. 9: NoBILl, G Faune carcinologique de la Mer Rouge. Decapodes et Stomatopodes. Annls Sci. nat. (Zool.) (9) 4: PARDI, L Researches on the coast of Somalia. The shore and the dune of Sar Uanle. Introduction. Monitore zool. ital. (N. S.) Suppl. 8: SERENE, R. & C. L. SoH New Indo-Pacific genera allied to Sesarma Say 1817 (Brachyura: Decapoda: Crustacea). Treubia 27: SERENE, R. & A. F. UMALI The family of Raninidae and other species of Brachyuran Decapods from the Philippines and adjacent regions. Philipp. J. Sci. 99 (1970): TwEEDIE, M. W. F Notes on grapsoid crabs from the Raffles Museum. Bull. Raffles Mus. 23: VANNINI, M. 1976a. Researches on the coast of Somalia. The shore and the dune of Sar Uanle. 8. Notes on Atelecyclidae and Portunidae (Decapoda Brachyura). Monitore zool. ital. (N.S.) Suppl. 8:

46 GRAPSIDAE OF SAR UANLE 101 VANNINI, M. 1976b. Researches on the coast of Somalia. The shore and the dune of Sar Uanle. 10. Sandy beach decapods. Monitore zoo!. ita!. (N. S.) Suppl. 8: VANNINI, M., G. CHELAZZI, L. CHELAZZI, A. ERCOLINI, F. FERRARA, G. MESSANA, P. MESSERI & L. PARDI Researches on the coast of Somalia. The shore and the dune of Sar Uanle. 13. Physical environment: geomorphological notes, climate and tides. Monitore zoo!. ita!. (N. S.) Suppl. 9: VATOVA, A I Decapodi della Somalia. ThJlassia 6 (2): Address of the first author: Dr. MARCO VANNINI, Istituto di Zoologia dell'universita, Via Romana 17, Firenze (Italia). I Monitore zool. ita!. (N. S.) Suppl. XIV: , 1981 I