PEREZ FARFANTE: SPERMATOPHORES OF AMERICAN WHITE SHRIMPS 



serving to receive the sperm immediately after its 

 release through the openings of the sperm sacs 

 Vi^hich lie immediately posteroventral to them; the 

 enclosure for the freed sperm is completed ven- 

 trally by the bases of the anterior lobes of the 

 spermatophores which are applied to sternite XII. 

 The coxal plates of the fourth and fifth pereopods 

 are relatively short but are directed mesially, 

 helping to keep the compound spermatophore in 

 position by supporting its lateral blades which lie 

 dorsal to them and which are firmly applied to the 

 thelycum. 



In P. schmitti, P. setiferus, and, particularly in 

 P. stylirostris, the coxal plates of the third 

 pereopods are large and directed posteriorly; thus, 

 they appear to aid in keeping the sperm masses 

 (projecting dorsally through the compound sper- 

 matophore) within the thelycal concavity of ster- 

 nite XIII. This is suggested by the fact that in the 

 former two species, in which the concavity lies on 

 the anterior part of sternite XIII, the coxal plates 

 are much shorter than in P. stylirostris in which 

 the double concavity is located on the posterior 

 part of the sternite. In P. schmitti and P. setiferus, 

 the coxal plates of the fourth and fifth pereopods 

 (longer in the latter) are directed mesially, sup- 

 porting the lateral components of the sperma- 

 tophore and pressing them against the thelycum. 

 In P. stylirostris, these coxal plates are larger than 

 in any of the other species, those of the fifth 

 pereopods offering a broad base for the attach- 

 ment of the anterior portions of the dorsal plates 

 of the spermatophore to their ventral surfaces. 

 The coxal plates of the fourth pereopods are 

 directed posteromesially, lying ventrad to the 

 subvertical shelf of sternite XIII, thus helping in 

 holding the sperm masses within the thelycal con- 

 cavities of the latter sternite. 



Finally, in all five species, the coxal plates are 

 provided with numerous long, mesially directed 

 setae which, in impregnated females, become em- 

 bedded in the dorsal plates or extend over the 

 blades and flanges, thus contributing to main- 

 taining the spermatophore in position. 



COMPARISONS OF SPERMATOPHORES 



The morphology of the spermatophores of two 

 species of the subgenus Melicertus have been 

 studied in rather considerable detail: that of P. (M.) 

 kerathurus (Forskal 1775) by Mouchet (1931) and 

 Heldt (1938a, b), and that of P. {M.)japonicus Bate 

 1888, by Kishinouye (1900), Hudinaga (1942) and. 



later, more meticulously by Tirmizi (1958). A brief 

 illustrated account of the spermatophore of P. 

 {Farfantepenaeusy duorarum duorarum 

 Burkenroad 1939, was presented by Eldred (1958). 

 Recently, Malek and Bawab (1974a, b), conducted a 

 thorough study of the formation of the sperma- 

 tophore within the vas deferens in P. (M.) 

 kerathurus; the hardened cover of the sperma- 

 tophore that is contributed by the ampulla is now 

 being investigated by them. The above studies, as 

 well as those on the subgenus Lifxypenaeus, have 

 revealed that in spermatophores of Penaeus the 

 sperm mass is surrounded by a gelatinous, multi- 

 layered (Malek and Bawab 1974b) sheath which, in 

 turn, is enclosed in a sperm sac; this usually bears 

 an aliform process, and in members of Li- 

 topenaeus additional attachment structures are 

 present. 



The principal characteristics of the sperma- 

 tophores of the five species of Litopenaeus are 

 presented in Table 1 to facilitate a comparison of 

 them. 



The spermatophore of P. vannamei is the 

 simplest. It lacks an anterolateral wing, is not 

 produced into an anterior lobe, and does not bear a 

 lateral blade.The fact that the ventral and lateral 

 walls are both opaque and thus almost indistin- 

 guishable, contributes to the relatively simple ap- 

 pearance of this spermatophore. However, it 

 exhibits by far the thickest lateral flap and the 

 largest dorsal plate. Apart from the seemingly 

 firm affixation of the anterior part of the sacs to 

 the thelycum, the attachment of the compound 

 spermatophore to the female is accomplished by 

 the very elongate dorsal plates, which support the 

 geminate body and the paired flanges. Finally, the 

 compound spermatophore when applied to the 

 female extends only to about the midlength of 

 sternite XIII, instead of reaching sternite XII as 

 do those of the other species. The short anterior 

 extensions of the ventral walls are applied to the 

 median protuberance of sternite XIII, and the 

 prominent bulges of the sacs, where the sperm 

 masses are concentrated, lie at the anterior part of 

 sternite XIV. Consequently, the sperm is released 

 farther away from the gonopores of the female 

 than in the remaining species. 



^he subgenus Farfantepenaeus was recently established by 

 Burukovskii (1972) to include the grooved species of Penaeus 

 (those with adrostral sulci extending posteriorly beyond 

 midlength of carapace) from American waters, one of them also 

 occurring off West Africa. These shrimps were previously placed 

 by P6rez Farfante (1969) in the subgenus Melicertus Rafinesque 

 1814, together with the grooved Penaeus occurring from the 

 eastern Atlantic eastward to the waters of Hawaii. 



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