NOTE 



DISTRIBUTION AND ABUNDANCE OF 



SICYONIA PENICILLATA LOCKINGTON, 



1879 IN THE GULF OF CALIFORNIA, 



WITH SOME NOTES ON ITS BIOLOGY 1 



Penaeid shrimp on the continental shelves of 

 Mexico are heavily exploited and represent one of 

 the major sources of seafood. It is also an impor- 

 tant source of revenue as most of the catch is ex- 

 ported. Of the different species which are commer- 

 cially fished, the genus Penaeus constitutes prac- 

 tically the entire catch (Dilio-Fuentes et al. 1976; 

 Klima 1981; Mathews 1981). In the Gulf of Califor- 

 nia, on the Pacific side of Mexico, there is a very 

 important trawl fishery for Penaeus (Farfan- 

 tepenaeus ) californiensis Holmes and, to a lesser 

 extent, for P. (Litopenaeus ) vannamei Boone and P. 

 (L.) stylirostris Stimpson which are both predomi- 

 nantly caught in coastal lagoons. Small catches of 

 P. (F ) breuirostris Kingsley are also taken in the 

 southern Gulf of California (Edwards 1978; 

 Mathews 1981). In the area, however, the fisheries 

 for Penaeus shrimp have shown a steady fall in 

 catch since 1962 (Lluch-Belda 1974; Rodriguez de 

 la Cruz 1981a). One of the major consequences has 

 been an increasing but still limited interest for the 

 bycatch of Penaeus shrimp and more attention has 

 recently been given to other species or genera that 

 were previously considered too small or not abun- 

 dant enough (Hernandez-Carvallo 1976; 

 Grande- Vidal and Diaz-Lopez 1981; Paul 1981). 

 Thus, other contributors to the total catch are 

 Xiphopenaeus riveti Bouvier, which has been in- 

 creasingly important in the Gulf of California 

 fishery since 1972 (Hernandez-Carvallo 1976), and 

 Trachypenaeus pacificus Burkenroad, which occa- 

 sionally appears in local markets, and has effec- 

 tively occupied a secondary part in recent fisheries 

 (Rodriguez de la Cruz 1981b; Mathews 1981). 



Although there are 19 species of Sicyonia re- 

 ported from American waters, little information 

 has been published on the relative importance 

 that the genus has or might have for fishery devel- 

 opment. Commercial catches have been reported 

 forS. breuirostris Stimpson along the coast of the 

 southeastern United States (Perez Farfante 1980) 



1 Contribution No. 341 of the Institute de Ciencias del Mar y 

 Limnologia, UNAM. 



and in the Gulf of Mexico (Arreguin-Sanchez 

 1981), and this species seems to be one of the most 

 abundant decapod crustaceans in these areas 

 (Kennedy et al. 1977; Huff and Cobb 1979; Soto 

 1980; Wenner and Read 1982). Comparatively, on 

 the Pacific coast of America, two species have been 

 occasionally caught in large quantities. Sicyonia 

 ingentis, the only species of the genus found north 

 of Mexico, is actively fished off the coast of Califor- 

 nia (Frey 1971; Mearns and Greene 1974), while in 

 the Southern Hemisphere, the importance of rock 

 shrimp in fishery activities has recently increased 

 and S. disdorsalis, one of the four species occur- 

 ring in the area, represented about 5.8% of the 

 total catch of penaeid shrimp in northern Peru in 

 1977 (Arana and Mendez 1978). Sicyonia disdor- 

 salis is also the dominant species in the southeast- 

 ern Gulf of California (Hendrickx et al. 1982) and 

 is commonly found as a member of the Penaeus 

 bycatch (Paul and Hendrickx 1980). 



The information in this paper was obtained 

 while processing the material collected during a 

 2-wk cruise in the Gulf of California, and it is 

 presented as a contribution to the study of the 

 biology and fishery of S. penicillata on the Pacific 

 coast of Mexico. Information related to the dis- 

 tribution, abundance, and habitat of the species in 

 the Gulf of California, biometric data, and natural 

 diet is also included. 



Material and Methods 



• Samples of benthic fauna were collected in May 

 1982 at 32 different sampling stations on the con- 

 tinental shelf of the Gulf of California, Mexico 

 (Fig. 1). Of these 32 collections, 28 were made with 

 an 11 m headrope commercial otter trawl, with a 

 stretched mesh of 6.5 cm, equipped with a 2.5 cm 

 bar mesh inner cod end bag. Four samples were 

 made with a 3 m wide rectangular oyster dredge 

 equipped with 2.5 cm bar mesh collection bags. 

 Tows were made from the 50 m RV El Puma, of the 

 Institute de Ciencias del Mar y Limnologia, Uni- 

 versidad Nacional Autonoma de Mexico, at speeds 

 of between 2 and 4 km/h and were about 30 min in 

 duration. At the end of each tow, samples were first 

 sorted into major groups (mollusks, crabs, shrimp, 

 echinoderms, and fish) and fresh weights for each 

 group were obtained to the nearest 100 g with 



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