Los ejemplares de congrio Conger conger L., 1758 provenientes de las campañas de primavera Medits (Mediterranean International Trawl Survey, primavera de 2002) y de otoño Grund (National Group for ...Demersal Resource Evaluation, otoño de 2001 y 2002) en el mar Adriático (Mediterráneo nororiental), entre 0 y 400 m de profundidad, tienen una longitud que oscila entre 21 y 130 cm y, con mayor frecuencia, entre 30 y 50 cm. La edad, determinada mediante la cuenta de los anillos y la medición del eje mayor de los estatolitos, se estima entre 3 y 8 años, con predominio de ejemplares de 4 y 5 años. El análisis histológico de las gónadas ha permitido identificar solo óvulos inmaduros. La dieta, más abundante en otoño, se constituye principalmente a base de Osteichthyes, Crustacea y Mollusca.
Specimens of conger eel Conger conger L., 1758 from Spring Medits (Mediterranean International Trawl Survey, Spring 2002) and Autumn Grund (National Group for Demersal Resource Evaluation, Autumn 2001 and 2002) trawl surveys in the Adriatic (Northeast Mediterranean) at depths of between 0 and 400 m, were found to measure in length from 21 to 130 cm, with greater frequency in the 30 to 50 cm range. Age determined on the basis of ring count and the length of the greater otolith axis was found to be between 3 and 8 years, with the majority of specimens in the 4- to 5-year range. Histological gonad analysis only revealed immature ovaries. The specimens were found to feed chiefly on Osteichthyes, Crustacea and Mollusca, which are most abundant in Autumn.
We assessed spatio-temporal genetic patterns in Mediterranean samples of bluefin tuna (BFT)to look for signs of population structuring and genetic erosion, which might be related to ...stockoverexploitation and depletion. We analyzed microsatellite variation at seven neutral loci onseven contemporary bluefin tuna samples collected from the Alboran Sea to the Levant Sea(N=316) and in two historical samples (N=99) collected from 1911 to 1926 in the southernTyrrhenian and Adriatic Seas. We found signs of widespread and deep spatial geneticstructuring in both contemporary (mean FST =0.014, P < 0.0001) and historical bluefin tunas(FST=0.020, P < 0.0001). These findings coherently confirm previous data obtained on alimited number of samples and reinforce the possibility that the Mediterranean is inhabited byreproductively isolated sub-populations. Temporal genetic analyses did not find evidence ofgenetic bottlenecks in Mediterranean bluefin tuna samples. However, since samples displayedheterogeneity of population demographic parameters, Mediterranean bluefin tunasubpopulations might have partially independent dynamics. Our results illustrate that inMediterranean, structured bluefin tuna populations retain a high level of genetic diversityacross space and time, despite possible demographic declines and population changes.
Se han evaluado los patrones genéticos espaciotemporales en las muestras mediterráneas deatún rojo (BFT) para hallar indicios de estructuración de la población y de erosión genética,que podrían estar relacionados con la sobreexplotación y agotamiento del stock. Se analizó lavariación microsatélite en siete loci neutrales de siete muestras de atún rojo contemporáneasrecogidas desde el mar de Alborán hasta el mar de Levante (N=316) y en dos muestrashistóricas (N=99), recopiladas desde 1911 hasta 1926 en el mar Adriático y Tirrenomeridional. Se hallaron signos de estructuración genética espacial muy marcada y extendidaen ambas muestras de atún rojo, contemporáneas (media FST =0,014; P < 0,0001) e histórica(FST=0,020; P < 0,0001). Estos hallazgos confirman con coherencia los datos anterioresobtenidos para un número limitado de muestras y refuerzan la posibilidad de que elMediterráneo esté habitado por subpoblaciones aisladas desde el punto de vista reproductivo.Los análisis genéticos temporales no evidenciaron embudos genéticos en las muestras de atúnrojo del Mediterráneo. Sin embargo, dado que las muestras presentaban cierta heterogeneidaden los parámetros demográficos de población, las subpoblaciones de atún rojo delMediterráneo podrían tener dinámicas parcialmente independientes. Nuestros resultadosilustran el hecho de que, en el Mediterráneo, las poblaciones estructuradas de atún rojomuestran un algo grado de diversidad genética en el tiempo y en el espacio, a pesar de losposibles descensos demográficos y cambios en la población.
Nous avons évalué les schémas génétiques spatio-temporels dans des échantillonsméditerranéens de thon rouge (BFT) en vue de rechercher des indices de structuration de lapopulation et d’érosion génétique, lesquels pourraient être liés à la surexploitation et à lararéfaction du stock. Nous avons analysé la variation micro-satellitaire chez sept locus neutresde sept échantillons contemporains de thon rouge prélevés de la mer d’Alboran à la merLevantine (N=316) et dans deux échantillons historiques (N=99) prélevés de 1911 à 1926 dansla mer Tyrrhénienne méridionale et la mer Adriatique. Nous avons trouvé des indices destructuration génétique spatiale très marquée et étendue dans les deux échantillons de thonrouge, contemporains (moyenne FST =0,014, P < 0,0001) et historiques (FST=0,020, P <0,0001). Ces découvertes confirment de façon cohérente les données antérieures obtenues surun nombre limité d’échantillons et renforcent la possibilité selon laquelle la Méditerranée esthabitée par des sous-populations isolées sur le plan de la reproduction. Les analysesgénétiques temporelles n’ont trouvé aucune preuve de goulets d’étranglement génétiques dansles échantillons de thon rouge de la Méditerranée. Toutefois, comme les échantillons ont faitapparaître une hétérogénéité dans les paramètres démographiques de la population, les souspopulationsde thon rouge de la Méditerranée pourraient avoir des dynamiques partiellementindépendantes. Nos résultats illustrent le fait qu'en Méditerranée, les populations structurées dethon rouge font apparaître un niveau élevé de diversité génétique dans le temps et dansl’espace, malgré d’éventuelles chutes démographiques et de possibles changements depopulation.
Features of the Marche marine fauna. - Following a preliminary description of the environmental situation which exists in the stretch of sea lying off the Marche coast an outline is presented of the ...main aspects of the benthic fauna as far as the territorial limits of Yugoslavian waters with emphasis on the importance to the Marche, from a naturalistic point of view, of the limited rocky zones opposite Monte Conero and Monte Castellaro.
After mentioning present trends in research on zooplankton in the area, consideration is given to the faunistic problems which have been created by fishing to different degrees and with different equipment on the entire biological community, at the same time proposing a valid method of approach to fishing problems.
Kurdela, Cepola macrophthalma (L.) je gonohorist. Starost je određena temeljem čitanja otolita. Utvrđeno je da mužjaci dosižu veće dužine od ženki. Tijekom razdoblja razmnožavanja mužjaci su znatnije ...zastupljeni u populaciji nego ženke.
The red bandfish Cepola macrophthalma (L.) is characterized by a gonochoristic sexual organization. Age was estimated from otolith readings. Males were found to reach a greater length than females. During the reproductive period the males prevail in comparison to the females.
A meta-analysis of the straight fork lengths (herewith abbreviated as L) of 2,458,028 Atlantic bluefin tuna, Thunnus thynnus (L.), taken from 224 scientific publications and unpublished L data from ...scientific organizations and fishing companies spanning most of the known Atlantic and Mediterranean Atlantic bluefin tuna fisheries dating from 1605 to 2011, give L values ranging from L
min
= 20 cm and L
max
= 330 cm. The results indicate that the parameter L
∞
= 318.85 cm of the growth equation used by ICCAT's Standing Committee on Research and Statistics Atlantic bluefin tuna assessment group for the eastern stock (Lt = 318.85 1 - e
−0.093 (t + 0.97)
) lies within the confidence limits of the maximum Ls presented in the study: L
max
= 319.93 ± 11.3 cm, confirming that this equation perfectly fits the biology of the growth of this species. These conclusions are also valid for the equation for the western stock (Lt = 314.90 1 - e
−0.089 (t +1.13)
). The ICCAT Atlantic bluefin tuna database contains numerous records of Atlantic bluefin tuna L outside the biological feasibility, and solutions are provided to recognize and remove these outliers based on the application of fixed values of Fulton's condition factor (K) between 1.4 and 2.6 and appropriate L-W relationships to correct this situation in the future.
Full text
Available for:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A meta-analysis of the straight fork lengths (herewith abbreviated as L) of 2,458,028 Atlantic bluefin tuna, Thunnus thynnus (L.), taken from 224 scientific publications and unpublished L data from ...scientific organizations and fishing companies spanning most of the known Atlantic and Mediterranean Atlantic bluefin tuna fisheries dating from 1605 to 2011, give L values ranging from Lmin = 20 cm and Lmax = 330 cm. The results indicate that the parameter Lmax = 318.85 cm of the growth equation used by ICCAT's Standing Committee on Research and Statistics Atlantic bluefin tuna assessment group for the eastern stock (Lt = 318.85 1 - e super(-0.093(t-0.97))) lies within the confidence limits of the maximum Ls presented in the study: L max = 319.93 plus or minus 11.3 cm, confirming that this equation perfectly fits the biology of the growth of this species. These conclusions are also valid for the equation for the western stock (Lt = 314.90 1 - e super(-0.089(t+1.13))). The ICCAT Atlantic bluefin tuna database contains numerous records of Atlantic bluefin tuna L outside the biological feasibility, and solutions are provided to recognize and remove these outliers based on the application of fixed values of Fulton's condition factor (K) between 1.4 and 2.6 and appropriate L-W relationships to correct this situation in the future.
Full text
Available for:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Kurdela, Cepola macrophthalma (L.) je gonohorist. Starost je određena temeljem čitanja otolita. Utvrđeno je da mužjaci dosižu veće dužine od ženki. Tijekom razdoblja razmnožavanja mužjaci su znatnije ...zastupljeni u populaciji nego ženke.
U radu su opisani novi nalazi crne voline Dipturus nidarosiensis (Storm, 1881) iz Jadran-skoga mora. Dva primjerka ulovljena su na području Južnojadranske kotline 2008. odnosno 2010. godine. Ovi ...nalazi proširuju saznanja o distribuciji ove rijetke dubokomorske vrste čija je prisutnost u Sredozemnom moru tek nedavno utvrđena.
U radu su opisani prvi nalazi dubokomorske vrste Chtenopteryx sicula
u Jadranskom moru. Pridnenom i pelagičnom mrežom ulovljeno je ukupno šest primjeraka ove rijetke vrste u sklopu istraživanja ...dubokomorskih zajednica u južnojadranskoj kotlini 2008 i 2010. godine. Primjerci su ulovljeni na dubinama do 1200 m te predstavljaju najdublji i ujedno najsjeverniji nalaz ove vrste u
Mediteranu. Dorzalna dužina plašta analiziranih jedinki kretala se od 21 do 60 mm. Samo u ženki nađeni su visceralni fotofori na ventralnoj strani vrećice sa crnilom. U radu su date nove informacije
vezane uz obilježja kljuna, uključujući detaljan opis pigmentacije. Broj zona prirasta u statolitima ukazuje na starost jedinki između tri i pet mjeseci. Utvrđena je pozitivna korelacija između dužine
statolita i broja zoni prirasta/starosti u danima. Makroskopski i histološki uzorci gonada potvrdili su da je jedna jedinka bila spolno zrela (kolovoz), četiri jedinke su bile u stadiju spolnog sazrijevanja
(svibanj i kolovoz), a dvije su bile spolno nezrele (ožujak). Rezultati ukazuju na to da proces spolnog sazrijevanja ove vrste u južnom Jadranu počinje u proljeće, dok se puna spolna zrelost doseže tijekom ljeta.
Morska zvijezda Astropecten irregularis (Pennant, 1777) je uobičajena vrsta u Jadranskom moru. Glavni ciljevi ovog istraživanja su bili ustanoviti njezinu distribuciju, biomasu i abundanciju na ...kontinentskoj podini otvorenih voda sjevernog i srednjeg Jadrana na osnovi eksperimentalnog uzorkovanja pridnenom kočom za vrijeme 11 putovanja ekspedicije Pipeta (1985.-1994.). Obavljeno je 518 potega pridnenom kočom na 56 unaprijed određenih stalnih postaja uzduž deset transekata, na različitim tipovima sedimenta na dubinama od 10 do 430 m. Vrsta A. irregularis je zabilježena u 82,2% potega, s najvećim vrijednostima indeksa biomase i abundancije na dubinama od 10 do 50 m. Najdublje je zabilježena tijekom potega od 313,5 do 412,5 m. Iako je vrsta zabilježena na cijelom istraživanom području, najabundantnija je bila na nekim područjima najsjevernijeg dijela Jadrana, te vrlo abundantna na područjima uzduž zapadne obale. Najveće srednje vrijednosti indeksa biomase i abundancije su zabilježene na pijesku-siltu-glini, siltoznom pijesku i pjeskovitom siltu te na glinovitom siltu i siltoznoj glini.
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