Management of threatened Aphanius Fasciatus at Il-Maghluq, Malta

Over the last decade the distribution of Aphanius fasciatus Nardo has regressed sharply across the Maltese Islands despite numerous legal conservation instruments. In this study we present the results of a one-year phenological study at the protected wetland site known as Il-Maghluq. The A. fasciatus population structure and a number of water physical characteristics were monitored. The biotic data collected was found to be consistent with that of a highly vulnerable population. The authors make a number of management recommendations to improve the conservation status of this population.peer-reviewe

Fin Spine Bone Resorption in Atlantic Bluefin Tuna, Thunnus thynnus, and Comparison between Wild and Captive-Reared Specimens

Bone resorption in the first spine of the first dorsal fin of Atlantic bluefin tuna (ABFT) has long been considered for age estimation studies. In the present paper spine bone resorpion was assessed in wild (aged 1 to 13 years) and captive-reared (aged 2 to 11 years) ABFT sampled from the Mediterranean Sea. Total surface (TS), solid surface (SS) and reabsorbed surface (RS) were measured in spine transverse sections in order to obtain proportions of SS and RS. The spine section surface was found to be isometrically correlated to the fish fork length by a power equation. The fraction of solid spine bone progressively decreased according to a logarithmic equation correlating SS/TS to both fish size and age. The values ranged from 57% in the smallest examined individuals to 37% in the largest specimens. This phenomenon was further enhanced in captive-reared ABFT where SS/TS was 22% in the largest measured specimen. The difference between the fraction of SS of wild and captive-reared ABFT was highly significant. In each year class from 1- to 7-year-old wild specimens, the fraction of spine reabsorbed surface was significantly higher in specimens collected from March to May than in those sampled during the rest of the year. In 4-year-old fish the normal SS increase during the summer did not occur, possibly coinciding with their first sexual maturity. According to the correlations between SS/TS and age, the rate of spine bone resorption was significantly higher, even almost double, in captive-reared specimens. This could be attributed to the wider context of systemic dysfunctions occurring in reared ABFT, and may be related to a number of factors, including nutritional deficiencies, alteration of endocrine profile, cortisol-induced stress, and loss of spine functions during locomotion in rearing conditions.Versión del editor4,411

Fatty Acids Profile, Atherogenic (IA) and Thrombogenic (IT) Health Lipid Indices, of Raw Roe of Blue Fin Tuna (<i>Thunnus</i> <i>thynnus</i> L.) and Their Salted Product “Bottarga”

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Gender Bias, Cognition, and Power in the Legal Academy

<p>Relationship of total spine surface, <i>TS</i>, to fork length, <i>FL</i>, for wild (solid line) and captive-reared Atlantic bluefin tuna (broken line).</p

Approximate geographical location of sampling areas for wild and captive-reared Atlantic bluefin tuna.

<p>Black and grey circles indicate sampling sites for wild and captive-reared specimens, respectively. 1, South Adriatic Sea; 2, South Tyrrhenian Sea; 3, North Ionian Sea (Gulf of Taranto); 4, Ionian Sea around Malta; 5, Puerto de Mazarrón and Cartagena, Spain; 6; Malta; 7, Vibo Marina, Italy; 8, Drvenik and Uglyan Island, Croatia.</p

Number of examined specimens subdivided per age.

<p>Age 1.25 year includes wild specimens of age class 1 captured from June to February and so on for the following age classes; age 1.75 year includes wild specimens of age class 1 captured from March to May and so on for the following age classes.</p><p>Number of examined specimens subdivided per age.</p

Cross section of the first ray of the first dorsal fin from two 6-year-old Atlantic bluefin tuna specimens.

<p>a) Wild specimen, <i>FL</i> = 154 cm. Arrows indicate the four visible annuli, 3^rd to 6^th; the first two annuli were reabsorbed. b) Captive-reared specimen, <i>FL</i> = 156 cm. Arrows indicate the three visible annuli (4^th to 6^th); the first three annuli were reabsorbed. The sections were cut above the spine condyle. c) and d) schematic view of photographs in a) and b), respectively, with unabsorbed bone areas highlighted in green and partially or totally reabsorbed areas in orange. Note the larger extension of the green area in the captive-reared specimen with respect to the wild one, which indicates a higher degree of bone resorption.</p

Progress of the mean ratio between spine section solid and total surfaces (<i>SS/TS</i>) with age in wild and captive reared Atlantic bluefin tuna; vertical bars: standard error of mean values.

<p>Progress of the mean ratio between spine section solid and total surfaces (<i>SS/TS</i>) with age in wild and captive reared Atlantic bluefin tuna; vertical bars: standard error of mean values.</p