Observations on Polycheles Sculptus S. I. Smith, 1880 (Decapoda, Palinura, Polychelidae) from Sardinian Waters (Central Western Mediterranean)

Abstract

We present the first data on the population structure, reproduction, and feeding ecology of Polycheles sculptus S. I. Smith, 1880 from the Sardinian sea. Samples were collected during experimental trawl surveys carried out in 2006-2007 in Sardinian waters, at depths between 1037 and 1598 m. A total of 72 specimens of P. sculptus, 31 males, 40 females, and 1 specimen of undetermined sex, was examined. The sex ratio of the whole sample showed a slight preponderance of females. No significant deviations from the expected 1 : 1 relationship were, however, found along the investigated depth range. A clear seasonality in reproduction was not determined. The species showed a high value of the stomach vacuity index (Cv). The diet was based on eight broad categories of preys, but no dominant prey was recognized. Females showed the greatest width in their diet, though Morisita's index indicated a large overlap between sexes.

Larval stages of the deep-sea lobster Polycheles typhlops (Decapoda, Polychelida) identified by DNA analysis: morphology, systematic, distribution and ecology

“…The highest peak of P. typhlops larval abundances during the summer agrees with the highest frequency of ovigerous females in the Mediterranean (Follesa et al 2007), and the bi-seasonal presence of larvae is in agreement with the fact that P. typhlops males are sexually active during the whole year (Cabiddu et al 2008;Gastoni et al 2010). The occurrence of P. typhlops larvae in deep plankton just above the adult populations is also in accordance with previous larval records.…”

“…Despite several taxonomic uncertainties have been clarified within this family in recent years (Ahyong 2009;Chan 2010), studies concerning the biology of polychelids are still lacking. There is some information available on the trophic role of these lobsters (Cartes 1993(Cartes , 1998Maynou and Cartes 1998;Cartes et al 2007;Gastoni et al 2010), but sampling difficulties have prevented scientists from understanding the ecology of polychelids in detail. Knowledge of the reproductive biology of deep-sea species is also scarce and mostly confined to a few species from deep continental slopes and hydrothermal vent habitats (Wenner 1979;Abelló and Cartes 1992;Mullineaux et al 1995;Maiorano et al 1998;Company and Sardà 1998;Company et al 2003;Follesa et al 2007;Cabiddu et al 2008).…”