PfeREZ FARFANTE: ROCK SHRIMP GENUS SICYONIA 



tuberance. The females of S. martini differ from 

 those of all the other Sicyonia occurring in the 

 region by possessing a conspicuous tubercle on the 

 anteromedian extremity of the plate of sternite 

 XIV. 



In addition to the distinguishing characters 

 cited above, S. martini exhibits other features that 

 differ from those of S. affinis. The dorsomedian 

 carina of the fifth abdominal somite is abruptly 

 truncate; the abdomen is coarsely tuberculate and 

 the tergal sulci on the third through fifth somites 

 are deep. Sicyonia martini also differs from S. 

 affinis in the barely to distinctly concave (instead 

 of convex) anterior margin of the pleuron of the 

 first somite; the anteroventral extremity of the 

 four anterior pleura which are markedly angular, 

 forming angles of about 90° or less, rather than 

 being rounded or broadly angular; and the outline 

 of the fourth abdominal pleuron which is subpen- 

 tagonal and often bears a spine on the posteroven- 

 tral angle, whereas in S. affinis it is subcircular 

 and always unarmed. 



Sicyonia martini differs further from S. 

 aliaffinis by the presence on the first abdominal 

 somite of a short but conspicuous longitudinal 

 ridge extending posteriorly from the ventral end of 

 the anteromedian pleural sulcus. The anterome- 

 dian and posteromedian pleural sulci of the second 

 and third abdominal somites are shorter than in 

 S. aliaffinis, extending dorsally only to about a 

 third of the height of the somite from the middor- 

 sal line rather than to a fourth, and the pos- 

 teromedian ones are curved anteriorly at their 

 dorsal extremities. Finally, S. martini lacks the 

 conspicuous purplish-brown mark (resembling a 

 longitudinally disposed "9" located posterior to the 

 hepatic sulcus and just ventral to the branchiocar- 

 diac carina) present in S. aliaffinis. 



Material. — 193 specimens from 41 lots. 



For list of records see Perez Farfante and Boothe 

 1981. 



Sicyonia picta Faxon 1893 

 Figures 47-52 



Sicyonia picta Faxon 1893:210 [syntypes: 4c? 29, 

 MCZ 4639, and 25 29, USNM 21172, off Golfo de 

 Panama (7°40'00"N, 79°17'50"W), 127 fm (232 

 m), 8 March 1891, Albatross stn 3387; 16 , USNM 

 21171, off Punta Mariato (7°12'20"N, 

 80°55'00"W), Panama, 182 fm (333 m), 23 Feb- 

 ruary 1891, Albatross stn 3355]. Faxon 

 1895:180, pi. 46, fig. 2, 2a-c. H. Milne Edwards 



and Bouvier 1909:244. De Man 1911: 

 112. Bayer et al. 1970:A97. Arana Espina 

 and Mendez G. 1978:27, fig. 10-13. Brusca 

 1980:256. Mendez G. 1981:47, pi. 10, Fig. 

 83-86. Perez Farfante 1982:372. 

 Eusicyonia picta. Burkenroad 1934a:95, fig. 35, 

 1934b: 126, 1938:87. Anderson and Lindner 

 1945:318. 



Vernacular names: rock shrimp, target shrimp, 

 Japanese shrimp (United States); cacahuete, 

 camaron de piedra, camaron de roca, camaron 

 japones (Mexico). FAQ names: peanut rock 

 shrimp (English), camaron cacahuete 

 (Spanish), boucot cacahouette (French). 



Diagnosis. — Antennal spine well developed and 

 buttressed. Second abdominal somite with dor- 

 somedian carina lacking incision. First pereopod 

 with basis and ischium unarmed. Postrostral 

 carina bearing one tooth posterior to level of he- 

 patic spine and raised in high, arched crest behind 

 posterior tooth. Abdomen with tooth on dorsome- 

 dian carina of first somite conspicuously larger 

 than posterior tooth on carapace. Petasma with 

 distal projection of dorsolateral lobule slightly 

 curved mesially, its compressed tip produced dor- 

 sally in strong, hooklike spine. Thelycum with 

 plate of sternite XIV flat or slightly elevated lat- 

 erally; posterior component of median plate flat or 

 slightly raised laterally. Branchiostegite with 

 ocellus consisting of red center svirrounded by yel- 

 low ring. 



Description. — Body relatively slender (Fig. 47). 

 Carapace sparsely studded with long setae and 

 bearing patches of shorter setae on dorsum; patch 

 also present anteroventral to hepatic sulcus, 

 another elongate obliquely disposed on bran- 

 chiostegite, and others on lateral depression and 

 anteroventral part of sixth abdominal somite. Ab- 

 domen with few small tubercles on first three so- 

 mites, most on row behind posterior sulci. 



Rostrum short, usually not overreaching distal 

 margin of eye, its length increasing linearly with 

 carapace length (Fig. 48), but proportionately 

 longer in young (0.40-0.25 cl); in males (Fig. 49fi), 

 weakly arched, subhorizontal or upturned, usu- 

 ally not more than 25° but occasionally 30°, deep 

 basally, gently narrowing to slender, short tip (Fig. 

 49A); in females, nearly straight, raised 25°-40°, 

 deep along almost entire length, slightly narrower 

 and truncate apically; in both sexes armed with 

 two to four dorsal teeth and two or three apical 



57 



