Morphology, sex ratio, and diet of Bothus podas (Delaroche, 1809) in Heraklion Bay, Crete (Greece)

Abstract

The aim of the present study is to provide morphometric relationships for the Mediterranean wide-eyed flounder Bothus podas (Delaroche, 1809), to identify possible sexual dimorphism, and to determine the feeding habits and the functional role of the species in the ecosystem. Sampling was carried out during a trawl survey off the coast of northern Crete in early May of 2015. A total of 425 specimens were examined (175 males and 250 females; total length (TL) range: 6.2-13.5 cm and 6.0-15.1 cm, respectively). The relationships between TL and weight, interorbital space (IO), body height (BH), and mouth dimensions (horizontal mouth opening: HMO, vertical: VMO mouth opening, and mouth area: MA) were all significant (P < 0.05) and of power types. The estimated value of the exponent b of the length-weight relationship (LWR) for sexes combined was 2.923. Sexual dimorphism was exhibited for the relationships between TL and IO, BH, VMO, HMO, and MA, whereas this was not true for the LWR. The diet spectrum of B. podas includes mainly benthic invertebrates and to a lesser extent small benthic fishes. On one occasion, an individual larva of Fistularia commersonii was recorded in the stomach contents of a male, and this is the first report of any predator of this Lessepsian invader in the Mediterranean.