Glavonošci kao plijen glavate želve, Caretta caretta (Reptilia: Cheloniidae), iz istočnog Tirenskog mora

This study presents the results of the examination of cephalopod remains extracted from the digestive tract of 40 loggerhead turtles, Caretta caretta, stranded along the Campanian coasts (Southern Italy, eastern Tyrrhenian Sea). We retrieved the remains of 23 cephalopods from 16 turtles (frequency of occurrence = 40%). They belonged to Sepia officinalis (19 specimens) and Octopus vulgaris (2 specimens), both of them benthic neritic species, and Histioteuthis reversa (2 specimens), an oceanic species. Accordingly, loggerheads appear to feed both on the bottom, seemingly in shallow waters, and in the open seawater column; both on muscular items (S. officinalis and O. vulgaris) and ammoniacal ones (H. reversa). This is the first record of H. reversa as a prey of the loggerhead turtle.Ova studija prikazuje rezultate istraživanja ostataka plijena izvađenih iz probavila 40 glavatih želvi, Caretta caretta, nasukanih duž obala Kampanije (južna Italija, istočno Tirensko more). Iz 16 kornjača izvadili smo ostatke 23 glavonošca (učestalost pojavljivanja = 40%). Pripadali su vrstama Sepia officinalis (19 primjeraka) i Octopus vulgaris (2 primjerka), koje su obje bentoske neritičke vrste, kao i oceanskoj vrsti Histioteuthis reversa (2 primjerka). Prema tome, čini se da se glavate želve hrane na dnu, vjerovatno u plitkim vodama, kao i u stupcu otvorenih morskih voda; i to mišićavim plijenom (S. officinalis i O. vulgaris) kao i plijenom bogatim amonijakom (H. reversa). Ovo je prvi zapis vrste H. reversa kao plijena glavate želve

Anatomical features of sex inversion in the rainbow wrasse,Coris julis

In an anatomical study of 206 Coris julis (L.) taken in the Bay of Naples from September '81 to August '82, we found gonad organization to vary with the seasons, and that inversion occurs not only in empty gonads at the end of the reproductive period, but also in ovaries in active vitellogenesis, before the reproductive period. According to the criteria adopted by Reinboth (1975) and Dipper & Pullin (1979) for the histological differentiation of a primary into a secondary testis, we observed that of 21 individuals with a primary testis. 17 had an initial, and 4 had a terminal, colour pattern. Our data agree substantially with those of Bacci and Razzauti (1957), but differ notably from Reinboth's (1975)

Further investigations into sex reversal ofCoris julisL. (Pisces, Labridae)

The morpho-histological analysis of 102 Coris julis kept under standard environmental conditions for more than three months and used for behavioural investigations has shown correlations between colour phases and gonadic state

Seasonal variability in voluntary dive duration of the Mediterranean loggerhead turtle, <i>Caretta caretta </i>

We characterised the effect of seasonal fluctuations in water temperature (Tw) on the nonventilatory period (NVP) of Mediterranean loggerhead turtles, Caretta caretta. Ten captive turtles, that were subject to the natural variations in Tw found in the Gulf of Naples, dived significantly longer when Tw decreased. More than 50% of summer and winter dives lasted between 2 and 10 min; the maximum dive duration (120 min) occurred in winter at a Tw of 13°C. The longest NVP coincided with a low level of activity and a lower food consumption. This, and a reduced metabolic rate consequent to acclimatisation to a low Tw were likely to have influenced NVP

First records of dive durations for a hibernating sea turtle

The first published record, from the early 1970s, of hibernation in sea turtles is based on the reports of the indigenous Indians and fishermen from Mexico, who hunted dormant green turtles (Chelonia mydas) in the Gulf of California. However, there were no successful attempts to investigate the biology of this particular behaviour further. Hence, data such as the exact duration and energetic requirements of dormant winter submergences are lacking. We used new satellite relay data loggers to obtain the first records of up to 7 h long dives of a loggerhead turtle (Caretta caretta) overwintering in Greek waters. These represent the longest dives ever reported for a diving marine vertebrate. There is strong evidence that the dives were aerobic, because the turtle surfaced only for short intervals and before the calculated oxygen stores were depleted. This evidence suggests that the common belief that sea turtles hibernate underwater, as some freshwater turtles do, is incorrect

Overwintering behaviour in sea turtles : dormancy is optional

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&deg;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&deg;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

Detection of erythrophagocytosis in loggerhead’s blood

The phagocytosis of red blood cells (RBCs) is due to changes on the erythrocyte surface: specific modifications of RBC membrane components, alteration of surface molecules, loss of RBC membrane phospholipid asymmetry and irreversible oxidative damage of SH groups (Bratosin et al., 1998). In man erythrophagocytosis by neutrophils and monocytes is detectable in the autoimmune hemolytic anemia associated with paroxysmal cold hemoglobinuria and has been observed in some patients manifesting clonal hematopoietic malignancies with myelodysplasia (Mukhopadhyay et al, 2003; Lewandowski et al., 2011). Phagocytosis by macrophages is a highly conserved phenomenon among vertebrates and it has been postulated that the pathophysiology of erythrophagocytosis may likewise be similar in reptiles and mammals (Nevill, 2009). In Caretta caretta the heterophils, analogous to the mammalian neutrophils, can phagocyte both parasitized and normal-appearing erythrocytes. On circulating blood smears stained with MGG-stained smears of circulating Caretta blood demonstrated that 4-51% of the heterophils were emitting pseudopodia that made contact with erythrocytes and that others had progressively encircled individual erythrocytes. These are mature erythrocytes containing a typical inclusion body, recognized as Heinz body (Basile et al., 2011). Moreover, teardrop-shaped RBCs were also identified in the blood films suggesting that the phagocytosing cell aspirates or selectively removes the inclusion body from the erythrocyte and permits the resultant dacrocyte to remain in the circulation. A comparable phenomenon, the pitting function of the spleen, is well know in man. In this case the phagocytic cells of the spleen remove remnants of DNA (Jolly bodies) from denucleated erythrocytes and allow them to persist in circulation. This pitting results in a efficient removal of the inclusion bodies contained in RBC cytoplasm by releasing dacryocytes into circulation. The positivity to ALP MPO and CAE reactions also confirmed that the loggerhead’s phagocyting cells are heterophils. In conclusion loggerhead’s erythrophagocytosis is a defense mechanism allowing both the complete degradation of infected/parasitized erythrocytes and the pitting of the inclusion body and the release of an healthy erythrocyte into circulation. References: Basile Filomena, Di Santi Annalisa, Caldora Mercedes, Ferretti Luigi, Bentivegna Flegra, Pica Alessandra. Inclusion bodies in loggerhead erythrocytes are associated with unstable hemoglobin and resemble human Heinz bodies. J. Exp. Zool. 313A DOI: 10.1002/jez.687. Bratosin D, Mazurier J, Tissier JP, Estaquier J, Huart JJ, Ameisen JC, Aminoff D, Montreuil J. (1998) Cellular and molecular mechanisms senescen erythrocyte phagocytosis by macrophages. A review. Biochimie 80, 173-195. Lewandowski K, Homenda W, Mital A, Complak A, Hellmann A. (2011) Erythrophagocytosis by neutrophils - a rare morphological phenomenon resulting in acquired haemolytic anaemia? Int J Lab Hematol. doi: 10.1111/j.1751-553X.2011.01312.x. Mukhopadhyay Sanjay, Keating Lawrence and Souid Abdul-Kader. (2003) Erythrophagocytosis in Paroxysmal Cold Hemoglobinuria. American Journal of Hematology 74:196–197

Allometric scaling of lung volume and its consequences for marine turtle diving performance

Marine turtle lungs have multiple functions including respiration, oxygen storage and buoyancy regulation, so lung size is an important indicator of dive performance. We determined maximum lung volumes (V-L) for 30 individuals from three species (Caretta caretta n = 13; Eretmochelys imbricata n = 12; Natator depressus n = 5) across a range of body masses (M-b): 0.9 to 46 kg. V-L was 114 ml kg(-1) and increased with Mb with a scaling factor of 0.92. Based on these values for VL we demonstrated that diving capacities (assessed via aerobic dive limits) of marine turtles were potentially over-estimated when the V-L-body mass effect was not considered (by 10 to 20% for 5 to 25 kg turtles and by &gt; 20% for turtles &gt;= 25 kg). While aerobic dive limits scale with an exponent of 0.6, an analysis of average dive durations in free-ranging chelonian marine turtles revealed that dive duration increases with a mass exponent of 0.5 1, although there was considerable scatter around the regression line. While this highlights the need to determine more parameters that affect the duration-body mass relationship, our results provide a reference point for calculating oxygen storage capacities and air volumes available for buoyancy control