Morphological study of the deep-water rose shrimp Parapenaeus longirostris (Lucas, 1846) (Crustacea: Decapoda: Dendrobranchiata: Penaeidae) in the eastern Ionian and Aegean Sea (Eastern Mediterranean Sea)

This is the first attempt to describe the relative growth of several characteristics in the deep-water rose shrimp Parapenaeus longirostris (Lucas, 1846) in the whole Mediterranean Sea. According to the median values, the morphometric characters of female and male individuals caught in the Aegean Sea were greater than those from the Ionian Sea. A negative allometry of swimming morphological characters (uropod, scaphocerite, telson) and of abdomen (related to the rapid locomotion, reproduction) was found in both sexes and areas. In contrast to this, the growth of the third pereiopod (involved in walking ability) in females from the Aegean Sea was positively allometric. Both sexes showed a positive allometry of rostrum length with size in both areas. The juveniles of both sexes showed proportionally longer morphological characters than the adult ones, indicating that the allometry differs for this species during its life cycle. The present study is of great interest to evolutionary biologists and to fishery managers providing an initial incentive for further investigation of this commercially important decapod in the whole Mediterranean.