Mantis shrimps are commercially important crustaceans in many areas of the world. In contrast to the relatively common studies of adults, limited studies have been attempted of larvae because of a lack of identification keys. The objectives of this study were two-fold: (1) to link wild-caught larval specimens from the Seto Inland Sea to a certain species and (2) to present a detailed morphological description of the last larval stage. The resulting molecular phylogenetic tree based on 16S rRNA gene sequences strongly implies that our larval specimens were linked to Levisquilla inermis, which was barcoded from a newly collected adult specimen with a morphological identification. K2P genetic divergence was found to be 0% among the larval and adult specimens. The congeneric species L. jurichi was the sister group of the L. inermis cluster, but the K2P distance between them was 3.4%, and it was considered a distinct species. Morphological observations provided five major distinguishing characteristics of the last-stage larva of L. inermis: (1) propodus of second maxilliped with three basal spines, (2) all five pleopods possessing an appendix interna with cincinnuli, (3) exopod of uropod longer than the endopod, (4) distal margin of the exopod of the uropod reaching the lateral tooth of telson, and (5) telson with nine intermediate denticles. Overall, our results reveal the importance of combining molecular and morphological analyses for solving stomatopod larval identification. This finding can be used to support and facilitate future research on the taxonomy and biodiversity of stomatopod larvae.

The population parameters of mantis shrimp (Squilla mantis Linnaeus, 1758) were studied regarding age composition, sex ratio, growth, survival and mortality rates, and the exploitation rate in the Aegean coasts of Turkey in 2013. We collected 936 specimens by shrimp gillnets along the coasts of Izmir Province from April to October 2013. The mean condition factor was K = 1.02 for both sexes, while the sex ratio was 58.7% for female and 41.3% male. Mean lengths, mean weight and length–weight relationship were calculated as TL = 12.57 ± 0.07 cm, CL = 3.02 ± 0.02 cm, W = 22.14 ± 0.37 g, W = 0.0098 × L3.02. Age determination was based on indirect ageing through length–frequency data using the Bhattacharya method. The age of the population varied from 0+ to 3+. Von Bertalanffy growth parameters were estimated as TL∞ = 19.69 cm, CL∞ = 4.74, W∞ = 79.41 g, k = 0.50 year−1 and t0 = −0.37 year. Mortality and exploitation rates derived as Z = 1.90, M = 1.16, F = 0.74 and E = 0.39, respectively.

New records of the mantis shrimp, Rissoides desmaresti, are presented from broad scale regional environmental characterization surveys of the south coast, eastern English Channel, River Thames and the east coast regions of the UK. These records include the most northern sampling of this species off the coast of the UK, and emphasize the importance of large scale surveys in providing important ecological information on nationally scarce species.

Eyes of stomatopod crustaceans, or mantis shrimps, contain the greatest diversity of visual pigments yet described in any species, with as many as ten or more spectral classes present in a single retina. In this study, the eyes of seven species of mantis shrimp from three superfamilies of stomatopods were examined for their content of retinoids. Only retinal and retinol were found; neither hydroxyretinoids nor dehydroretinoids were detected. The principal isomers were 11 -cis and all-trans. The eyes of most of these species contain stores of 11 -cis retinol, principally as retinyl esters, and in amounts in excess of retinal. Squilla empusa is particularly noteworthy, with over 5000 pmoles of retinol per eye.