Manuel Ayón-Parente

A new deep-water species of Odontozona (Decapoda: Stenopodidea: Stenopodidae) from the East Pacific, and new record of O. foresti Hendrickx, 2002

A new species of the stenopodid shrimp Odontozona is described from deep-water off the west coast of Mexico. It is distinguished from the three other species of the genus known in the area, from O. rubra Wicksten, 1982, and O. foresti Hendrickx, 2002, by the absence of a series of spines on the posterior half of the carapace, behind the post-cervical groove, and from O. spongicola (Alcock & Anderson, 1899) by the presence of spines on the ventral margin of somites 1-5 (smooth in O. spongicola) and by the much slender third pair of pereiopods in the new species. A new record is provided for O. foresti, and the first male specimen, the third specimen on record, is compared with the female holotype.

Records of mud shrimps (Crustacea: Decapoda: Axiidea and Gebiidae) from Pacific Mexico

A total of 75 specimens belonging to four species of thalassinoids were collected in the intertidal and estuarine zones of two localities along the Pacific coast of Mexico. Callianassa tabogensis is recorded for the first time in Mexico, and is transferred to the genus Neotrypaea . Material of Callichirus is assigned to Callichirus seilacheri with some doubts due to taxonomic problems related to this genus in the eastern Pacific. Neocallichirus cf. grandimana , an amphi-American species described for the western Atlantic and previously reported in Ecuador and along the Pacific coast of Panama and Colombia, is reported for the first time in Mexico. Upogebia dawsoni is recorded for the second time from the coast of Jalisco. An updated list of Axiidea and Gebiidea known from the Mexican Pacific is provided, including 35 species.

Two new species of deep-water Caprella (Peracarida, Amphipoda, Caprellidae) from the Pacific coast of Mexico collected during the TALUD XIV cruise, with a checklist of species of Caprellidae recorded for the eastern Pacific

Two new deep-water species of the genus Caprella are described from the central Gulf of California, Pacific coast of Mexico. Caprella calderoni new species is distinguished from the 32 previously recorded species of Caprella from the eastern Pacific by its smooth forehead and pereonites, body not particularly slender, gnathopod 2 inserted at about mid-length of the second pereonite, elongated gills and gnathopod 1, the relative length of antenna 2 articles, length of the flagellum of antenna 1, the lack of an antero-lateral projection on pereonites 2 and 3, and the length-height proportion of pereonite 1. It is close to C. striata Mayer, 1903, recorded from Alaska. Caprella striata, however, features a different number of articles in the antenna 1 flagellum, two latero-posterior spines on pereonites 6, a small dorsal tubercle on pereonites 5 and 6, and a poison spine on the propodus of gnathopod 2 (all lacking in the new species). The buccal appendages also present significant differences. Caprella mercedesae new species, belongs to a group of eastern Pacific species with a sharp spine on the forehead. It is distinguished from all these species by a combination of characters, including the general shape of the body (not robust), the insertion level of gnathopod 2, its general shape, and the relative length of its dactylus, the relative length of antennae 1 and 2, the shape and relative length of the gills, the proportionally shorter or longer pereonites, and the presence of dorsal tubercles on at least pereonites 5-7 (absent in the new species).

Caprella suprapiscis sp. nov. (Crustacea: Amphipoda: Caprellidae) from the Pacific coast of Mexico.

A new species of caprellid, Caprella suprapiscis sp. nov., is described based on several specimens collected from Bahía Chamela, Jalisco, Mexico. All specimens were found in association with the scorpionfish Scorpaena mystes. Caprellids are set on the dorsal surface of fishes. The species is distinguished by head with a short dorsal projection, eyes distinctive, body slender and smooth, peduncular articles of antenna 1 not setose, antenna 2 with swimming setae, gnathopod 2 with three ventral projections in males. The species is close to C. californica, C. mercedesae, and C. scaura for a sharp spine on the forehead but can be distinguished by gnathopod 2 finely setose, and basis of gnathopod 2 shorter.

A new species of Munidopsis (Anomura, Galatheoidea, Munidopsidae) from the Gulf of California, western Mexico

A new species of Munidopsis Whiteaves, 1784 is described from the SW Gulf of California, western Mexico. The new species differs from all other known species of Munidopsis of the East Pacific by the presence of numerous antero-posteriorly compressed processes on the carapace, many of which are truncate and with crenulated anterior margin, by its oval-shaped carapace, wider in its posterior half, and by the short, subrectangular, narrow rostrum with an upturned distal portion. It also differs from the East Pacific species and other species of Munidopsis by the densely pitted carapace and appendages.

Notes on two species of Processa (Decapoda: Processidae) from the Mexican Pacific

Material belonging to the genus Processa, held in the Regional Marine Invertebrates Collection in Mazatlan, Mexico, is revised including specimens of the widely distributed P. peruviana, and the scarcely collected P. hawaiensis. For comparative purposes with the specimens from Hawaii and other localities, a detailed description of a male of P. hawaiensis collected in continental Mexico is provided, including illustrations of all appendages. Small differences are noted with previous description and partial redescriptions of this species, including proportion between propodus and dactylus of the fourth pereopod, and between merus and carpus of the right cheliped. In addition, the shape and setation of the first pair of pleopods in the Mexican material differs from the description of P. hawaiensis based on African material.

New records of the deep-sea anemone Phelliactis callicyclus Riemann-Zurneck, 1973 (Cnidaria, Actiniaria, Hormathiidae) from the Gulf of California, Mexico

Specimens of a deep-sea anemone were observed in photographs and video footage taken with the Remotely Operated Vehicle JASON (WHOI Deep Submergence Laboratory) in the Gulf of California, Mexico, in May 2008. Comparison of our material with photographs and description of this species available in literature indicate that the sea anemones filmed during the JASON survey are most likely to represent Phelliactis callicyclus Riemann-Zurneck, 1973. This species has previously been reported from a locality in the Gulf of California near the present record. During the JASON survey, 28 specimens of P. callicyclus were spotted in 27 locations during six dives. The specimens occurred on angular rock outcrops along the escarpments of the transform faults of the Gulf of California, between depths of 993-2543 m and at temperatures ranging from 2.3 to 4.5°C. Based on these new records, Phelliactis callicyclus appears to be widely spread in the Gulf of California.

Redescription and taxonomic status of Paguristes weddellii (H. Milne Edwards) (Crustacea: Anomura: Paguroidea: Diogenidae) from the eastern Pacific

The type and additional material of Paguristes weddellii (H. Milne Edwards, 1848) were examined. The species is redescribed and illustrated in details. Comparison of P. weddellii with the monotypic genus Tetralobistes Ayón-Parente & Hendrickx, 2010b, shows many similarities, principally in the armature of the distal margin of the male first pleopod and the shape of the telson, which in both cases feature a tetralobular posterior margin, a character considered unique among the Diogenidae. Consequently, Pagurus weddellii is transfered to the genus Tetralobistes. Paguristes hirtus Dana, 1851, a subjective junior synonym of Pagurus weddellii is removed from the synonymy based on lack of direct evidences.

First zoeal stage of the hermit crab Enallopaguropsis guatemoci (Glassell, 1937) (Crustacea: Anomura: Paguroidea: Paguridea) obtained in the laboratory

The first larval stage of Enallopaguropsis guatemoci is described in detail and illustrated. The larva is compared with larvae known for other genera of Paguridae except Pagurus. A synthesis of all characters provided herein indicates that first larvae of E. guatemoci can be separated from all known pagurid larvae (except Pagurus) by the combination of the following characters: carapace with long dorsal carina, posterolateral spines absent; abdominal somites 3-5 with pair of moderately long spines; telson narrowly triangular, not forked; spine at antennal protopod as long as endopod.

New records and description of two new species of carideans shrimps from Bahía Santa María-La Reforma lagoon, Gulf of California, Mexico (Crustacea, Caridea, Alpheidae and Processidae)

Abstract Two new species of the family Alpheidae: Alpheus margaritae sp. n. and Leptalpheus melendezensis sp. n. are described from Santa María-La Reforma, coastal lagoon, SE Gulf of California. Alpheus margaritae sp. n. is closely related to A. antepaenultimus and A. mazatlanicus from the Eastern Pacific and to A. chacei from the Western Atlantic, but can be differentiated from these by a combination of characters, especially the morphology of the scaphocerite and the first pereopods. Leptalpheus melendezensis sp. n. resembles L. mexicanus but can be easily differentiated because L. melendezensis sp. n. has the anterior margin of the carapace broadly rounded and has only one spine on the mesial margin of ischium in the major cheliped, versus an acute rostrum and an unarmed major cheliped. Additionally, a phylogenetic analysis was used to explore the relationships of these two new taxa. These results show that Alpheus margaritae sp. n. and Leptalpheus melendezensis sp. n. are indeed related to the species against which we are comparing them, and demonstrate that they can be considered as different species. Additional specimens of Leptalpheus cf. mexicanus, Ambidexter panamensis and A. swifti are recorded for the first time in the Santa María-La Reforma coastal lagoon.