Distribution and some biological parameters of the red gurnard, Chelidonichthys cuculus (Actinopterygii, Scorpaeniformes, Triglidae) in the north-central Adriatic Sea

Background. Red gurnard, Chelidonichthys cuculus (Linnaeus, 1758), is distributed in the Mediterranean Sea, Black Sea, and in the eastern Atlantic Ocean from Norway to Mauritania, although it is rarely found in the North Sea and on the Norwegian shelf. The aim of this work was to conduct a comprehensive study of red gurnard in the Adriatic Sea on selected aspects the population biology and some of its environmental implications . Materialsandmethods. The sampling covered the entire subdivision GSA17 (north-central Adriatic Sea) and it was based on several bottom trawl surveys of MEDITS and GRUND projects from 2000 through 2009. Biometric parameters, as well as the spatial- and depth distributions were analyzed. The parameters such as the length–weight relation, sex, gonad maturity stage, and the stomach content were determined on a subsample of 539 specimens collected seasonally (summer and autumn–winter) within 2007–2009. The data were processed statistically . Results. Chelidonichthys cuculus was mainly distributed in the central Adriatic. Juveniles showed a distribution in shallower waters while adults tended to migrate towards the Croatian coast at greater depths. The total length of the fish sampled ranged from 40 to 303 mm (TL). We assumed the length of 100 mm as a threshold separat ing juveniles from adults and the length range of 170–190 mm as the maturity size for females and males. Isometric- and allometric growth patterns were showed for the juveniles and the adults, respectively. The diet was based almost exclusively on crustaceans (IRI% > 98%) and it did not change upon reaching the sexual maturity. Chelidonichthys cuculus should be considered a specialist predator feeding mostly on necto-benthic lophogastrids (IRI% > 72%) . Conclusion. This work constitutes an attempt to summarize some environmental and biology aspects of the red gurnard in Adriatic population: differences in depth distribution and growth were found between juveniles and adults but not in diet. Males and females showed differences in growth parameters. Extending the studied area and collecting data of red gurnard in the main areas of production should help in better understanding the biolo gy and dynamics of this species

Chelidonichthys cuculus. In: Sartor P., Mannini A., Carlucci R., Massaro E., Queirolo S., Sabatini A., Scarcella G.

The Chelidonichthys cuculus biology is little known inMediterranean Sea and especially in the Italian seas. In Italian seas, reproduction takes place from January to June. In the Adriatic Sea males attain sexual maturity at smaller sizes than females: about 50% of males were mature at 15.0 cm TL and 50% of females were mature at 16.5 cm TL. The size at first sexual maturity for females in the Tyrrhenian is slightly greater of that of other areas. The Maximum length reached by this species is around 45 cm TL. In the Northcentral Adriatic Sea, a maximum length of 30 cm TL was reported. The area showing the greatest persistence of recruits was detected North of Pomo/Jabuka Pit, at a depth range between 100 and 200 m. The data relating to biomass and density evaluation refer to average catch indexes found during MEDITS trawl surveys since 1994 to 2013. The highest densities were observed in the waters of Sardinia, while lower densities were observed in the North-central Adriatic Sea and in the southern Tyrrhenian Sea

Eutrigla gurnardus. In: Sartor P., Mannini A., Carlucci R., Massaro E., Queirolo S., Sabatini A., Scarcella G., Simoni R., (eds). Synthesis of the knowledge on biology, ecology and fishery of the halieutic resources of the Italian seas.

The biology of the species in the Italian seas is little known. In the North-central Adriatic Sea a maximum size of 29 cm TL is reported for this species. The most common sizes reported for trawling surveys in the North-central Adriatic Sea range from 8 cm to 14 cm TL. Maximun age was estimated in 5 and 8 years for males and females, respectively, in the Aegean Sea and 3 and 4 years in the Aegean Sea. In Atlantic Ocean (France) maximum age was esimated in 15-16 years. Length-weight relationship parameters may vary according to age (juveniles and adults specimens) and sex. There is evidence of an increase in b values with latitude, from North to South. Reproduction takes place from early spring to August. In the northern-middle Adriatic Sea, males attain sexual maturity at smaller sizes than females: 50% of males attain maturity at around 12.2 cm TL, while 50% of females at around 15.0 cm TL. Sexual dimorphism related to size at maturity can be found also in other geographical areas, with clear differences in the size associated with latitude). In the northern-middle Adriatic Sea, grey gurnard recruits (<10 cm TL) were generally detected in the whole range of distribution of the species, although juveniles were mostly concentrated in the middle Adriatic Sea. The area showing the greatest persistence of recruits was found north of the meso-Adriatic Pit around the 100 m bathymetric line

Trigloporus lastoviza. In: Sartor P., Mannini A., Carlucci R., Massaro E., Queirolo S., Sabatini A., Scarcella G.

Few data are available on Trigloporus lastoviza biological cycle characteristics in the Italian seas. Trigloporus lastoviza, streaked gurnard, morphology, ecology, diet, biology, growth, sexual maturity and reproduction, recruitment, evaluation, stock assessment. Females reach larher sizes than males in middle-northern Adriatic Sea and in other areas. In the Adriatic Sea, it is reported a size between 11 and 26 cm TL with a main cohort at 16 cm TL. The estimated maximum age is of 5 years for both males and females; 6 and 8 years for males and females respectively in the Greek Aegean Sea; 6 and 5 years in the Turkish Aegean Sea 4 and 5 years in the Tunisian Aegean Sea. From a comparison between the regression parameters of the length-weigth relationship in different areas, there is evidence of an an increase of b values with latitude, from North to South. In the Italian seas, T. lastoviza spawns in summer. In the Greek Aegean Sea reproduction occurs between winter and early spring. In the Gulf of Tunis, gonadal maturation occurs from September to December and spawning takes place from late December to January for both sexes. In the middle-northern Adriatic Sea, streaked gurnard recruits (<11 cm TL estimated according to Bhattacharya\u2019s method, 1967) ) were found mainly along the North-eastern coast; the area showing the highest persistence in time of recruits was identified off the the Pag Island. A decrease in the number of recruits was observed with time, with a mean value of 4 recruits per km2

Note su distribuzione e \u201caree di nursery\u201d di due specie di triglidi (Scorpaeniformes) nel Nord-Centro Adriatico.

Il ruolo degli habitat costieri come nurseries del novellame di specie ittiche \ue8 fondamentale in relazione alla conservazione ed alla gestione delle risorse alieutiche. Ancora oggi il concetto di nursery \ue8 ambiguo ed \ue8 necessario considerare la combinazione di vari fattori, quali densit\ue0, accrescimento, sopravvivenza del novellame e migrazione verso gli habitat degli adulti, per determinare se un habitat \ue8 utilizzabile come nursery per il reclutamento dei giovanili. A tale scopo \ue8 stata condotta un\u2019analisi su distribuzione e aree di nurseries del capone coccio, Aspitrigla Cuculus (L.) e del capone ubriaco, Trigloporus lastoviza (Bonnaterre, 1788) in Adriatico (GSA 17) fra il 1996 e il 2008. I risultati preliminari mostrano che l'area di distribuzione di A. Cuculus copre tutto l'Adriatico centrale (ad eccezione delle acque profonde della fossa di Pomo/Jabuka) e le zone costiere occidentale e orientale dell\u2019Adriatico; i giovanili sono distribuiti principalmente in mare aperto nell\u2019Adriatico centrale; l'area di nursery che mostra il maggiore indice di persistenza (PI> 0.75) risulta sul fondo molle a nord della fossa di Pomo/Jabuka tra 100 e 200 m di profondit\ue0. Si conferma quindi che l'area a ridosso e all\u2019interno della fossa di Pomo/Jabuka rappresenta una delle principali aree di nursery per molte specie demersali, indicandone la notevole influenza sulle attivit\ue0 di pesca. I risultati preliminari relativi a T. lastoviza mostrano che \ue8 distribuita principalmente nella parte mediana ed orientale dell'Adriatico settentrionale e nella zona del canale fra Spalato e Dubrovnik, generalmente fino a 100 m di profondit\ue0; i giovanili sono concentrati soprattutto lungo la costa nord-orientale; l'area di nursery che mostra il maggiore indice di persistenza (PI> 0.75) \ue8 stata individuata al largo dell'isola di Pag

Depth distribution of gurnard species (Scorpaeniformes: Triglidae) from GSA 17.

The depth distributions of three gurnard species, Chelidonichthys cuculus, Eutrigla gurnardus and Trigloporus lastoviza, were analysed using MEDITS data in Adriatic Sea. Abundance were related to depth stratum showing species specific differences: different bathymetric distribution were highlighted for recruits and spawners of C. cuculus while no different pattern were found for E. gurnardus and T. lastoviza