FISHERY BLXLETIN: \0L. 69. NO. 3 



Seminal receptacles derived from paired, deep 

 invaginations at anterolateral extremities of 

 sternite XIV. In impregnated females, seminal 

 receptacles enclosing main component of sperm- 

 atophores, consisting of thin walled sac contain- 

 ing subspherical masses of spermatozoa. 



COLOR 



Juveniles recently caught in inshore water of 

 Oaxaca, Mexico, light buff with brownish red 

 suffusion; transverse, dark reddish brown bands 

 on posterior part of abdominal somites; bands 

 convex anteriorly, with widest portion on mid- 

 dorsal line, extending ventrally and forming 

 patch on posterior half of pleuron. Preserved 

 adults (fresh ones not observed by me) with 

 distinct dark abdominal bands, similar to those 

 in juveniles. 



SIZE 



Largest specimen examined, ? 40.5 mm car- 

 apace length, about 150 mm total length, from 

 off La Tapada, Chiapas, Mexico, depth 7-9 m. 

 Males smaller than females, largest observed 

 i allotyije, 26 mm carapace length, 108 mm total 

 length. 



DISTRIBUTION 



T. ftiscina has been found in the Golfo de 

 Tehuantepec, along the coasts of Oaxaca and 

 Chiapas, Mexico, and in the Golfo de Guayaquil, 

 as far south as Tumbes, Perii. Although this 

 species and T. faoea are sympatric in the Golfo 

 de Guayaquil, apparently T. fuscina ranges 

 farther north, since T. faoea has not been found 

 along the southwestern coast of Mexico. 



REMARKS 



T. fnscina is veiy closely related to T. faoea, 

 but differs from it in several aspects — mainly 

 in features of the telson (Figure 3A). In T. 



fuscina the posteriormost pair of spines is longer, 

 and fixed instead of movable, this being the only 

 member of the genus Trachypeyuieus with im- 

 movable spines on the telson; the anterior three 

 pairs of telsonic spines are stronger than in T. 

 faoea, particularly those spines at the lateral 

 base of the posteriormost pair; also the median 

 sulcus is well marked as far as the base of the 

 terminal portion of the telson. In T. fuscina the 

 platelike base of the anterior part of sternite XIV 

 in females (Figure 5A) is naked, and its lateral 

 margins curve strongly posteromesially, giving 

 rise to a deep emargination at the junction of 

 the plate with the posterior part of the thelycum 

 (sternite XIV). In males, the median plate of 

 sternite XIII narrows anteriorly, usually taper- 

 ing to a point (Figure 4F). 



It should be pointed out that during copulation 

 in this species, as well as in T. faoea, the male 

 transfers to each seminal receptacle a very thin 

 sac containing the spermatozoa, which are 

 grouped into subspherical masses. These masses 

 are not individually transmitted to the seminal 

 receptacles as believed by Burkenroad (1934b), 

 a phenomenon considered by him to be typical 

 of the genus TrcLchypenaeiis. 



ETYMOLOGY 



Fuscina, h., = three-pronged foi"k — referring 

 to the trifid appearance of terminal portion of 

 telson. 



Trachypenaeus faoea LOESCH AND AVILA 



FIGURES 3B, 4G, 5B 

 "CEBRA," "TIGRE," "INDIO," "CARABALI" 



T rachypeneus faoe Lindner, 1957 [part], nomen 

 nudum: 34, 35, 42, 43, 48, 49, 60, 61, 133, 134. 

 —U.S. Fish and Wildlife Service, 1962: 2, 6.— 

 Croker, 1967 [part] : 8, 19, 30, 39, 47, 57. 



Trachypeneus faoea Loesch and Avila, 1964: 

 4-8, 16, 21, 24-28, fig. 8b, 13b.— Avila and 

 Loesch, 1965: 3, 5, 6, 9, 10, 16, 19, 20, 23, 24, 

 fig. 4b. 



Trachypenaeus face. — Food and Agriculture Or- 

 ganization of the United Nations, 1965: 10. 



642 



