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Morphometric relationships and condition factors are essential for understanding any marine species' development process, which aids in designing appropriate strategies for management and articulating their balance in the ecosystem — and this includes shrimps. Since only a few studies on these characteristics have been done in Penaeus semisulcatus over the last thirty years, constant updating of these criteria is required to successfully manage the shrimp fishery in Palk Bay. The CL-TW relationship demonstrates negative allometric growth in both males and females, whereas the TL-TW relationship exhibits positive allometric growth. In this present investigation, significant differences in slopes and elevations of the carapace length-total weight, total length-total weight, carapace length-total length, and total length-carapace length have been observed between sexes; considering the condition factors shown in the present investigation, the shrimps in Palk Bay were in good growing condition. This study has demonstrated that updated information on morphometric relationships would help fishery managers effectively manage the fisheries. [ABSTRACT FROM AUTHOR]

This study examines the impact of shrimp trawling on the multi-species shrimp and prawn fishery in the northeastern Mediterranean. Fishing trials were carried out on a commercial prawn trawler between 18 and 23 September 2006. Data were collected with a conventional trawl net, designed specifically for prawns. During six valid trawl hauls, 32 species were caught in total and of the 17 species regarded as commercially valuable, individuals of all sizes of 12 species and those of the relatively larger sizes of 5 species were retained. The other 15 species were discarded as these are regarded as non-commercial due to a lack of market demand. The discard ratio was calculated as 2.37 : 1 for this fishery. The length-frequency distribution of the targeted penaeid prawn, Marsupenaeus japonicus, shows one peak at about 33 mm CL, and the larger specimens, over 35 mm, are all females (25%). However, the also targeted Penaeus semisulcatus shows two major peaks, at 29 and 39 mm CL, and the approximate size ranges connected with those peaks extend from 26 to 32 mm and from 36 to 40 mm CL, respectively; larger specimens, over 34 mm, are all females (37%). The female-male ratio was 1.07 : 1 for M. japonicus and 1.99 : 1 for P. semisulcatus. In the framework of by-catch and discard evaluation, this fishery should be defined as having high by-catch and discard rates. For this reason, gear-based and management-based solutions or measures should be developed to secure those resources for the future, and also to decrease the impact of fisheries on non-targeted species and their stocks. [ABSTRACT FROM AUTHOR]

The size structure of the commercially important rose shrimp, Parapenaeus longirostris, was compared between populations in the Sea of Marmara and the Aegean Sea. The analysis was based on data collected during trawl selectivity surveys carried out in November and December 2006. Growth showed no similar pattern, and in additions differences were found in length frequency distribution, sex ratio, and recruitment pattern of the P. longirostris populations in these two areas. [ABSTRACT FROM AUTHOR]

Three new species of the genus Megokris, M. manihine sp. n. and M. halli sp. n. from the South China Sea and the East China Sea, and M. motohburiorum sp. nov. from the Philippines, are described. In these three new species, the rostral teeth as well as the dorsal carinae on abdominal somites 2-6 are very similar to the corresponding structures in Megokris granulosus (Haswell, 1879) from Torres Strait, Queensland, and M. pescadoreensis (Schmitt, 1931) from Taiwan. However, the thelycum and petasma are characteristically different: in M. halli sp. n., the anterior plate of the thelycum bears a longitudinal middle protuberance, which is largely concave laterally in its middle region, and elevated with a round projection in its posterior part; and the anterior plate of the thelycum does not reach the posterior margin of the seminal receptacle. In M. manihine sp. n., the anterior plate of the thelycum bears a median longitudinal protuberance with a median ridge, the posterior part of which is conspicuously elevated with a pair of lateral swellings; the anterior plate of the thelycum does not reach the posterior edge of the seminal receptacle. In M. motohburiorum sp. n., the prominent median protuberance of thelycum is narrow in its anterior half and broadened with an elevation in its posterior half, while the posterior margin is rounded; the anterior plate of the thelycum is connected with the posterior edge of the seminal receptacle. [ABSTRACT FROM AUTHOR]

Two new penaeid shrimp, Megokris akademik sp. nov. and M. ghamrawyi sp. nov., are described from the Persian Gulf (= Arabian Gulf). These new species are most closely similar to M. granulosus (Haswell, 1879) from Darnley Island, Torres Strait, in the morphology of the thelycum, with an anterior median concavity, and in the petasma, with an anterolateral projection of an ox-horn shape, tapering at the tip, and directed forward. However, M. akademik and M. ghamrawyi differ from M. granulosus in the posterior margin of the anterior plate of the thelycum, which in the two new species is not fused with the posterior plate as it is in that latter species; also, in M. ghamrawyi the ventromedian process of the petasma has a rounded distal end, whereas in M. granulosus the petasma bears a triangular projection at the distal end of its ventromedian process. [ABSTRACT FROM AUTHOR]

The penaeid shrimp, Metapenaeopsis sibogae (De Man, 1907) was previously known only from deep waters in Indonesia and the Philippines. In the present study, the occurrence of this species was reported for the first time from Japanese waters, based on twenty-one specimens collected from Kagoshima Bay, southern Japan, between 130 and 148 m depth. As a result of morphological examination, the ratio of rostrum length to carapace length was found a useful character to distinguish M. sibogae from the sympatric species, M. lata Kubo, 1949, and subspecies, M. provocatoria owstoni Shinomiya & Sakai, 2000. The body colouration of live specimens of M. sibogae is also described. [ABSTRACT FROM AUTHOR]