José Salgado-Barragán

Branchiomma bairdi : a Caribbean hermaphrodite fan worm in the south-eastern Gulf of California (Polychaeta: Sabellidae)

Branchiomma bairdi , a fouling non-indigenous sabellid polychaete has been detected in the south-eastern Gulf of California, representing the first record in the eastern tropical Pacific, as its original distribution is the Caribbean Sea. The species was commonly found as isolated specimens but small aggregates with 4–12 individuals were also found on floating docks, on dock pilings, buoys and on hulls of vessels in the port of Mazatlan. Branchiomma bairdi is a simultaneous hermaphrodite with male and female gametes developing separately in the same segments. The sperm morphology suggests that the species is a free-spawner with external fertilization (ect-aquasperm type). A complete diagnosis is provided and a discussion about its systematics, reproduction and ecology is included.

The False Mussel Mytilopsis adamsi Morrison, 1946 (Mollusca: Bivalvia: Dreissenidae) in the Pacific Waters of Mexico: A Case of Biological Invasion

The false mussel Mytilopsis adamsi, originally described from the Pacific coast of Panama, is reported for the first time as an introduced species in the Urías estuary and an adjacent shrimp farm, on the Pacific coasts of Mexico. In the 19th century, this species was transported from the Pacific coast of Panama, reaching the Indo-Pacific Ocean, but it had not been previously reported in other coasts of the American Pacific. Its recent and irregular presence in this small estuary near shore the Mazatlán harbor and an adjacent shrimp farm suggests that the species was introduced into the area but it cannot still be considered as a harmful invader. The presence of the species in the shrimp farm may indicate that it was introduced along with shrimp stocks from Central America, although its passive transportation to the estuary via ballast water or attached to hulls is not discounted.

Abundance and diversity of macrofauna (fish and decapod crustaceans) in Penaeus vannamei culture ponds in Western Mexico

Abstract Polyculture involving shrimp and fish has not been developed in western Mexico. Shrimp farming along the west coast of Mexico has been estimated to occupy a total of 8000 ha, producing about 0.90 tons ha −1 in 1993. Abundance and diversity of macrofauna (fish and decapod crustaceans) associated with culture (MAC) of Penaeus vannamei were determined twice in a year, in a shrimp farm located 25 km south of Mazatlan, Sinaloa, SE Gulf of California, Mexico. A total of 4978 specimens of MAC was obtained; 2355 in June 1993 and 2623 in January 1994, totalling about 115 kg of fresh weight (0.34 to 0.87% of shrimp harvest). Fish represented 98.3% and 98.0% of specimens and 90.2–93.5% of total fresh weight; the rest were swimming crabs ( Callinectes ). The abundance of Pomadasys macracanthus, Lile stolifera , and Dormitator latifrons mexicanus was high and remarkably constant at both harvests. Maximum diversity was observed in winter (January 1994). Dominance by fresh weight reflects the importance of Pomadasys macracanthus in both cycles, and of Cynoscion xanthulus in the second. Largest fish were Gobiomorus maculatus (19.0 cm total length (TL)) and Elops affinis (36.5 cm TL). When comparing sizes, fish showed either a very clear ( P. macracanthus, M. altipinnis and G. cinereus ), slight ( L. stolifera and D. latifrons mexicanus ) or obscure ( C. xanthulus ) displacement towards higher values in the second, longer cycle. Callinectes arcuatus , the only abundant decapod crustacean harvested, also showed a remarkable stability as far as population size, fresh weight and size distribution were concerned.

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.

Panopeid Crabs (Crustacea: Brachyura: Panopeidae) Associated with Prop Roots of Rhizophora Mangle L. in a Tropical Coastal Lagoon of the Se Gulf of California, Mexico

Xanthid crab communities associated with aerial roots of the mangrove Rhizophora mangle L. remain poorly known. Aspects of their ecology were studied in a survey from 1993 to 1995 in the upper portion of the Urias lagoon, Mazatlan, an anti-estuary type coastal lagoon in NW Mexico. The species collected were Panopeus mirafloresensis (81.3%), Eurypanopeus canalensis (15%), P. chilensis (1.3%), P. purpurem (1.1%), Hexapanopeus beebei ( M (49%), M>F (37%) and F=M (14%). Eurypanopeus canalensis was more abundant in the upper lagoon where a 1:1 sex ratio was encountered.

Larval development of the eastern Pacific mud crab Acantholobulus mirafloresensis (Abele and Kim, 1989) (Decapoda: Brachyura: Panopeidae) described from laboratory-reared material

Summary The complete larval development of the eastern Pacific mud crab Acantholobulus mirafloresensis is described and illustrated from laboratory-reared material. The larval development consists of four zoeal stages and one megalopa. Comparison of A. mirafloresensis with descriptions of A. bermudensis and A. schmitti from the western Atlantic, shows that the first zoea of all three species seems to be identical, whereas major differences appear between the species at the zoea II to megalopa stages, mostly related with setation of carapace, mouthparts and abdomen.

Redescription of the poorly known pea crab, Pinnixa plectrophoros Glassell, 1935 (Decapoda: Pinnotheridae), from the Gulf of California

A complete redescription of the pinnotherid crab, Pinnixa plectrophoros Glassell, 1935, is presented. Glassells original description of P. plectrophoros, although without any accompanying illustrations, includes a series of morphological characteristics that help, to a certain extent, correctly identify the specimens of the species. A detailed examination of the holotype and specimens collected from Bahía Santa María-La Reforma, Sinaloa, in the central Gulf of California, revealed that the species has features, such as spines and tubercles, which were not mentioned in the original description. The original description of Pinnixa plectrophoros by Glassell (1935b) is hereby modified on the basis of the holotype, deposited in the San Diego Natural History Museum (SDNHM) and fresh material from Sinaloa, central Gulf of California, including illustrations and a photograph of color in life. The specimens from Sinaloa correspond to the second record of the species, 870 km southeast of the type locality.

Stomatopods (Malacostraca, Hoplocarida, Stomatopoda) in a shallow coastal lagoon in western Mexico

Stomatopods are essentially species of truly marine, i.e., salt water. Some species, however, have been collected in coastal systems where brackish water conditions occur (Dittel, 1991; Ahyong et al., 1999; Vasconcelos et al., 2017). One typical example is that of Cloridopsis dubia (H. Milne-Edwards, 1837), which has repeatedly been collected in coastal lagoons and in shallow muddy environments along its distribution range (Hendrickx & Salgado-Barragán, 1991; Lazarus & Cantera, 2017). A recent survey of shallow water in a costal lagoon system located in the SE Gulf of California, unveiled the presence of Lysiosquilla manningi Boyko, 2000, a name assigned to material described by Stimpson (1857) based on a specimen of C. dubia (see Hendrickx & Salgado-Barragán, 2017). Further sampling in the same ecosystem indicates that three other species of stomatopods inhabit the same coastal lagoon in addition to the previously reported C. dubia (for which an additional record is provided) and L. manningi. This material is reported herein. All specimens were deposited in the Regional Collection of Marine Invertebrates (ICML-EMU, followed by catalogue number). Abbreviations used are: CL, carapace length; TL, total length.

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.