Special Issue for Prof. Jacques Forest

Special Issue for Prof. Jacques Forest A NEW DEEP WATER SPECIES OF ODONTOZONA HOLTHUIS (DECAPODA, STENOPODIDAE) FROM THE SOUTHERN GULF OF CALIFORNIA, MEXICO BY MICHEL E. HENDRICKX 1 / Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, UNAM, P.O. Box 811, Mazatlán, Sinaloa 82000, Mexico ABSTRACT Odontozona foresti, a new deep water species of Stenopodidae is described from the southern Gulf of California, Mexico. The holotype, an ovigerous female, was collected with a benthic sledge at 1240-1270 m depth. The new species, the largest currently known for this genus (total length, 60.6 mm), is distinguished from other species of Odontozona by the lack of dorsal spines on the telson, the presence of long, anteriorly directed horizontal spines on the posterior margin of both cervical and postcervical grooves, and the absence of spines on the carapace behind these grooves. Unlike most species of the genus, the propodus and carpus of the fourth pereiopod are undivided, while these segments are divided into 2 indistinct segments in the fth pereiopod. The armature of the carapace resembles that of O. spongicola but in O. foresti the carapace is not swollen and the postcervical groove extends to about midheight of the lateral face of the carapace. RÉSUMÉ Odontozona foresti, une nouvelle espèce de Stenopodidae d eaux profondes, est décrite du sud du golfe de Californie, Mexique. L holotype, une femelle ovigère, a été récoltée à l aide d une drague benthique à 1240-1270 m de profondeur. L espèce nouvelle, la plus grande connue de ce genre de Stenopodidae (longueur totale: 60,6 mm) se distingue des autres espèces de Odontozona par l absence d épines dorsales sur le telson, la présence, sur les bords postérieurs des deux sillons cervicaux, de longues épines horizontales, dirigées vers l avant et par l absence d épines sur la carapace à l arrière de ces sillons. Contrairement à la plupart des espèces de Odontozona, le propode et le carpe des quatrièmes péréiopodes ne sont pas divisés tandis qu ils sont divisés en deux segments indistincts sur le cinquième péréiopode. L armature de la carapace ressemble à celle de O. spongicola, mais chez O. foresti, la carapace n est pas dilatée et le sillon postcervical s étend seulement jusqu à mi-hauteur de la face latérale de la carapace. 1 / e-mail: michel@mar.icmyl.unam.mx c Koninklijke Brill NV, Leiden, 2002 Crustaceana 75 (3-4): 405-412 Also available online: www.brill.nl

406 MICHEL E. HENDRICKX INTRODUCTION Stenopodidea are small to medium-sized shrimps that live in shallow or deep water. The group comprises two families, with a total of 9 genera (Holthuis, 1993). The genus Odontozona Holthuis, 1946 belongs to the family Stenopodidae and is represented in the eastern Paci c by two species: Odontozona rubra Wicksten, 1982, endemic to the Gulf of California, and O. spongicola (Alcock & Anderson, 1899) described from the Andaman Sea and recently recorded off California, U.S.A. (Wicksten, 1982; Goy, 1992). Eight other species of this genus are distributed worldwide (Dounas & Koukouras, 1989; Manning & Chace, 1990). During sampling activities on the mid and lower slope in the eastern Gulf of California (TALUD project), a large specimen of Odontozona was collected, different from both Odontozona rubra and O. spongicola. Review of literature dealing with other known species of Odontozona indicates that the collected specimen belongs to an undescribed species. The holotype is deposited in the Invertebrate Reference Collection of the Mazatlan Marine Station, UNAM, in Mazatlan, Mexico (EMU-5378). SYSTEMATICS Odontozona foresti new species ( gs. 1-3) Material examined. Holotype. Female, ovigerous, carapace length 16.5 mm, total length 60.6 mm, length of third pereiopod 39.0 mm, Station 34 (25 ± 43:5 0 N 109 ± 53:7 0 W), TALUD VI cruise, 17 March 2001, 1240-1270 m, deep water sledge (EMU-5378). Diagnosis. Large, pink coloured, robust stenopodidean shrimp. Rostrum with 14 small dorsal and one large ventral teeth. Cervical cincture complete, postcervical cincture extending midheight of lateral side of carapace, both with long, anteriorly directed horizontal spines; no spines on carapace posterior to cinctures. No dorsal spines on telson. Propodus and carpus of the fourth pereiopod undivided, of the fth divided into 2 indistinct segments. Description. Rostrum compressed, blade-like, wide, almost straight, about 2/5 length of carapace, reaching distal end of antennular peduncle and about half scaphocerite length, armed dorsally with 14 small irregularly set dorsal teeth, the posterior 2-3 situated posterior to hind margin of orbit, and ventrally with one large tooth ( g. 1A). Carapace robust, compressed dorso-ventrally, with deep cervical and postcervical grooves, latter groove well developed laterally, vanishing dorsally; posterior margin of cervical groove bearing cincture of 22 strong, anteriorly directed horizontal spines, the dorsal spines shorter; posterior margin of postcervical groove with 7 strong spines (six strong an a lower, smaller spine

ODONTOZONA FORESTI NOV. 407 Fig. 1. Odontozona foresti new species, female holotype (EMU-5378). A, lateral view, pereiopods and pleopods not represented; enlarged dorsal view of eye (a1) and lateroventral view of anterior margin of carapace (a2) (arrows); B, cephalothorax, dorsal view; C, telson and uropods, dorsal view. Scale bar, 5 mm.

408 MICHEL E. HENDRICKX on left side) similar to spines on the cervical groove ( g. 1A-B); one intermediate spine on right side of carapace; posterior margin concave, unarmed. Antennal and branchiostegal (doubled on left side) spines much smaller than lateral spines of cervical cincture; a strong, bi d spine, similar in size to cincture spines between branchiostegal and pterygostomial spines; pterygostomial angle with one sharp spine, another medium size spine posterior to it, both similar to antennal spine, and two (one on right side of carapace) marginal minute spines; supraorbital and hepatic spines strong, similar in size to postcervical cincture spines, hepatic spine just above wide, elevated branchial ridge. Postrostral carina not reaching cervical groove. Abdomen ( g. 1A) smooth, robust, dorsally unarmed, without median carina and without transverse grooves. First abdominal somite with a deep anterolateral cavity to receive posterolateral part of carapace, a ventral notch on pleuron margin where cavity opens; 2nd and 3rd abdominal somites with less developed anterolateral cavity, fold-like, where the posterolateral margin of anterior somite ts; margins of pleura 1-2 rounded, spineless; that of somites 4-5 almost straight, with 2-4 posteroventral small spines; 6th abdominal somite with strong lateral spine just above ventral margin, and with acute posterolateral angle. Telson ( g. 1C) about twice as long as 6th somite, 3.75 times as long as wide, deeply sulcate mesially in proximal half, armed with paired strong lateral teeth near midlength, smaller tooth at each posterolateral angle; no dorsal teeth. Eyes ( g. 1A, a1) small, without pigment, tipped with conical tubercle; distal part of peduncle with one blunt lateral spine and pair of sharp mesial spines. Antennular peduncle ( g. 3F) with basal segment unarmed dorsally, one strong ventrally directed ventral spine; stylocerite short, falciform, blunt, narrowly separated from proximal part of basal segment; 2nd segment unarmed, except for 1-2 minute mesial spinules; agella subequal, about twice as long as carapace. Scaphocerite ( g. 3G1, G2) about 3.5 times as long as wide, strongly concave laterally, hollowed in ventral view, armed with 4 teeth (not visible dorsally) in addition to distolateral spine. Mouthparts as illustrated ( g. 2), all fringed with setae. Third maxilliped with a two-segmented exopodite; ischium without spines; ventral margin of merus with one distal spine and a second spine at about 2/3 of segment length, measured from proximal margin, both spines small; carpus, propodus, and dactylus spineless ( g. 2G). First pereiopod ( g. 3A) small, slender, unarmed, ngers shorter than palm, merus and carpus of about same length; cutting edge of ngers pectinate in distal half. Second pereiopod ( g. 3B) similar to 1st, unarmed, merus shorter than carpus, both segments longer than in 1st pereiopod; cutting edge of ngers pectinate in distal half.

ODONTOZONA FORESTI NOV. 409 Fig. 2. Odontozona foresti new species, female holotype (EMU-5378), left buccal appendages. A, mandible, ventral view; B, same, dorsal view; C, maxillule; D, maxilla; E, rst maxilliped; F, second maxilliped; G, third maxilliped. Setae ommited, except on maxillule. Scale bars, 2 mm. Third (right) pereiopod ( g. 3C1, C2) of female holotype the largest and strongest, about 0.6 times body length; dactylus about 2/5 length of chela, one spine on dorsal margin of chela, close to dactylus articulation; carpus slightly shorter than chela, armed with one distodorsal strong spine, two subterminal spines and two similar spines at midlength, the latter four visible in ventrolateral view; merus shorter than carpus, a pair of spines on both lateral surfaces; ischium about 2/3 as long as merus, one strong distolateral spine. A large, triangular tooth, proximally on dactylus inner margin, which ts between two proximal teeth on

410 MICHEL E. HENDRICKX Fig. 3. Odontozona foresti new species, female holotype (EMU-5378). A, left rst pereiopod; B, left second pereiopod; C, right third pereiopod, outer view (C1), and inner view of chela (C2); D, left fourth pereiopod and enlarged dactylus (d1); E, left fth pereiopod; F, antennular peduncle, dorsal view; G1, scaphocerite, dorsal view; G2, same, laterodorsal view, showing peduncular segments of antenna. Scale bars, 2 mm.

ODONTOZONA FORESTI NOV. 411 inner margin of propodus; distal half of ngers with inner margin bearing minute chitinous lamellae; nger tips sharp, crossing. Left third pereiopod missing. Fourth pereiopod ( g. 3D) unarmed, with biunguiculate dactylus, unguis short, curved, tooth on exor margin strongest ( g. 3d1); propodus and carpus not subdivided, propodus with about 8 spinules on exor margin; ischium about 1/2 merus length; merus slightly shorter than carpus; propodus about 1/2 carpus length. Fifth pereiopod ( g. 3E) unarmed, with biunguiculate dactylus, unguis short, curved, tooth on exor margin strongest; propodus and carpus divided into 2 indistinct segments; propodus with about 9 spinules on exor margin; ischium about 1/2 merus length; merus slightly shorter than carpus; propodus about 1/2 carpus length. First pleopod uniramous; second to fth pleopods biramous; all pleopods without appendices or spines. No spines on sternum. Uropods ( g. 1C) shorter than telson, with lateral branch unarmed, except for short, blunt distal spine; mesial branch unarmed, longer than lateral branch. Two dorsal carinae on endopod and exopod. Eggs. Forty-two slightly oval eggs, about 1:6 2:0 mm. Habitat. Odontozona foresti was sampled at 1240-1270 m depth, on a muddy bottom. The oxygen concentration measured near the bottom was 0.86 ml O 2 =l. Adverse, hypoxic conditions at bottom level are shared with a small community of decapod crustaceans dominated by species of Munidopsis Whiteaves, 1874 and caridean shrimps (Hendrickx, 2001). Etymology. This species is named in honour of Prof. Jacques Forest, Muséum national d Histoire naturelle, Paris, on the occasion of his 80th birthday, to acknowledge his enormous contribution to decapod crustacean systematics. Remarks. Odontozona foresti is clearly distinguished from all other species of the genus by the lack of dorsal spines on the telson, the presence of long, anteriorly directed horizontal spines on the posterior margin of both cervical and postcervical grooves, and the absence of spines on the carapace behind these grooves. Unlike most species of the genus, the propodus and carpus of the fourth pereiopod are undivided, while these segments are divided into 2 indistinct segments in the fth pereiopod. The armature of the carapace resembles that of O. spongicola, but in this species the carapace is swollen and the postcervical groove reaches the dorsal margin, while in O. foresti the carapace is not swollen and the postcervical groove extends to about midheight of the lateral face of the carapace. Deep water Odontozona includes O. spongicola and O. edwardsi (Bouvier, 1908). All other known species are from shallow water (i.e., less than 30 m deep). Odontozona foresti also appears to be a very large species within the genus, almost

412 MICHEL E. HENDRICKX three times as large as O. spongicola, the largest of the previously known deep water Odontozona species (26.0 mm total length; Goy, 1992). ACKNOWLEDGEMENTS The author thanks scientists, students, and crew members who took an active part in the TALUD VI cruise. Special thanks to Graciano Valenzuela who prepared gs. 1 and 2, to Mercedes Cordero who edited the nal version of the manuscript, and to Joseph W. Goy for his comments on species of Odontozona. Material was collected with the support of CONACyT, Mexico (project 31805-N). REFERENCES ALCOCK, A. & A. R. ANDERSON, 1899. Natural history notes from H.M. Royal Indian Marine Survey ship Investigator. Commander T. H. Heming, commanding. Series III. No. 2. An account of the deep-sea Crustacea dredged during the surveying season of 1897-98. Ann. Mag. nat. Hist., (7) 3: 278-292. BOUVIER, E. L., 1908. Sur les relations zoologiques des crevettes de la tribu des Sténopidés. C. R. hebd. Séances Acad. Sci., Paris, 146: 887-891. DOUNAS, C. & A. KOUKOURAS, 1989. Odontozona minoica, new species, from the eastern Mediterranean Sea (Decapoda: Stenopodidea). Journ. Crust. Biol., 9 (2): 341-348. GOY, J. W., 1992. Systematics and zoogeography of eastern Paci c stenopodidean shrimps (Crustacea: Decapoda). Proc. San Diego Soc. nat. Hist., 22: 1-6. HENDRICKX, M. E., 2001. Occurrence of a continental slope deep-water decapod crustacean community along the edge of the minimum oxygen zone in the southeasterngulf of California, Mexico. Belgian Journ. Zool., 131 (Suppl. 2): 71-86. HOLTH UIS, L. B., 1993. The recent genera of the caridean and stenopodidean shrimps (Crustacea, Decapoda) with an appendix on the order Amphionidacea: 1-328. (Nationaal Natuurhistorisch Museum, Leiden). MANNING, R. B. & F. A. CHACE, JR., 1990. Decapod and stomatopod Crustacea from Ascension Island, South Atlantic Ocean. Smithson. Contrib. Zool., 503: 1-91. WICKSTEN, M. K., 1982. Two species of Odontozona (Decapoda: Stenopodidea) from the eastern Paci c. Journ. Crust. Biol., 2 (1): 130-135. First received 1 June 2001. Final version accepted 31 August 2001.