Thirteen loggerhead turtles Caretta caretta were released (10 from Naples, Italy, 2 from Monastir, Tunisia, 1 from Gallipoli, South Italy) with satellite relay data loggers (SRDL) to elucidate their overwintering behaviour. Nine turtles were successfully tracked throughout the winter, while 4 SRDLs failed to transmit after short deployment periods. Of these 9, 4 remained within 80 km of the release site, 3 travelled to a distant overwintering site, and 2 continued to move and did not remain within 80 km of a specific site. Apart from these differences, all turtles stayed near the coast and dedicated most of their time to dives lasting 3 h and longer. Maximum dive durations ranged from 270 to 480 min and were highly correlated with water temperatures, which fell below the supposed 15°C threshold for sea turtle hibernation in all overwintering sites. Median dive depths were between 4 and 24 m and were, thus, well within the mixed layer, as revealed by temperature profiles, which also were relayed by the SRDLs. No evidence was found that the turtles preferred warmer temperatures to overwinter in, because the range of temperature was very narrow on both the horizontal and the vertical scale of their movements. Despite the long resting phases and the low temperatures (minimum = 11.8°C) all turtles retained activity to some degree, at least to commute between the depth of resting and the surface to breathe. While the degree of winter dormancy is certainly affected by temperature, turtles were by no means obligatory hibernators, and their ability to move and even forage during the winter may be important for their growth and maturation rates, as well as their reproductive output.

Four species of stingrays of the genus Dasyatis occur in the Gulf of Gabès, but the taxonomic status of one of them, D. tortonesei has been questioned by several authors, and synonymized with D. pastinaca by some. The present study, using morphological comparisons and genetic analyses, demonstrates that there is a closely related species to D. pastinaca in the Gulf of Gabès, but distinguishable by several characters. This species is provisionally identified as Dasyatis cf. tortonesei, pending a more extensive comparative study including specimens from other regions of the Mediterranean Sea and eastern North Atlantic Ocean.

Background: One specimen of Carapus acus was captured in the Gulf of Gabès (southern Tunisia, central Mediterranean Sea), during an experimental bottom trawl survey in the frame of the monitoring of benthic fish stocks of the Tunisian coast. This represents the first record of the pearl fish in the area and a proof of the occurrence of this species in Tunisian coast. Results: The pearl fish caught measured 136.1 millimeters and it weighed 2.838 gram. It has been captured at the following coordinate 34°39'629"N; 12°45'795"E by 100 meters depth. Many Echinoderms were landed during this hauls but any Holoturoidea were observed. Conclusions: Carapus acus occurs in Tunisian water but others studies are necessary to confirm its abundance, the commensal or parasitic status usually attributed to the carapidae and to determine the host of this species in the Gulf of Gabès.

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