North-easternmost record of <i>Halosaurus ovenii</i> Actinopterygii: Notacanthiformes: Halosauridae) in the Mediterranean Sea, with notes on its biology

A single adult female specimen of Halosaurus ovenii Johnson, 1864 was captured by trammel nets at a depth of about 200 m off the coast of Arbatax (Sardinia, Italy) in early April 2007. Macroscopic and microscopic analysis of the gonad showed a postspawning ovary. This is the fourth documented capture of this fish in the Mediterranean Sea, representing the north-easternmost record for this species in this geographic area. Furthermore, the present specimen was fished at the shallowest depth ever recorded before

Características reproductivas de un pez vivíparo de la zona batial Cataetyx alleni (Osteichthyes, Bythitidae) en el sureste del mar de Cerdeña (Mediterráneo centro-occidental)

The reproductive biology of the bathyal viviparous fish Cataetyx alleni was described based on 34 specimens (17 females and 17 males) caught during experimental trawl surveys carried out between 800 and 1700 m depth in the southeastern Sardinian Sea (central-western Mediterranean). Males and females were present at similar size intervals. For the first time, the internal fertilization was demonstrated by the finding of free spermatozoa scattered in the ovarian cavity. Based on macroscopic and histological gonad analysis, mature females were found in summer, autumn and winter, suggesting a long reproductive period. Inseminated females were observed only in November and January, in correspondence with the higher maturity of the males. These results suggest a probable reproductive peak with copulation in autumn-winter. Moreover, histological examination demonstrated that the ovaries of this member of the family Bythitidae had a ‘group-synchronous’ pattern. No spermatophores in males and embryos in females were observed in the histological sections analysed.La biología reproductiva de Cataetyx alleni, un pez vivíparo batial, fue descrita basándose en el examen de 34 especímenes (17 hembras y 17 machos) capturados durante las campañas experimentales de pesca de arrastre conducidas entre 800 y 1700 metros de profundidad en el sureste del mar de Cerdeña (Mediterráneo centro-occidental). Hembras y machos presentaron tallas similares. Por primera vez, la fecundación interna fue demostrada gracias al descubrimiento de espermatozoos libres dispersos en la cavidad del ovario. Basándose en análisis macroscópicos e histológicos, las hembras maduras fueron encontradas en verano, otoño e invierno, sugiriendo un periodo reproductivo muy largo. Las hembras fecundadas fueron observadas sólo durante el mes de Noviembre y Enero, conjuntamente con los machos de madurez máxima. Estos datos podrían suponer un posible máximo reproductivo con cópula durante el otoño y el invierno. Además, los exámenes histológicos demostraron que los ovarios de este Bythitidae presentan un modelo de sincronización de grupo. Ningún espermatóforo ni embriones fueron observados en las secciones histológicas analizadas

Reproductive characteristics of the bathyal viviparous fish <i>Cataetyx alleni</i> (Osteichthyes: Bythitidae) from the southeastern Sardinian Sea (central-western Mediterranean) MARIA

The reproductive biology of the bathyal viviparous fish Cataetyx alleni was described based on 34 specimens (17 females and 17 males) caught during experimental trawl surveys carried out between 800 and 1700 m depth in the southeastern Sardinian Sea (central-western Mediterranean). Males and females were present at similar size intervals. For the first time, the internal fertilization was demonstrated by the finding of free spermatozoa scattered in the ovarian cavity. Based on macroscopic and histological gonad analysis, mature females were found in summer, autumn and winter, suggesting a long reproductive period. Inseminated females were observed only in November and January, in correspondence with the higher maturity of the males. These results suggest a probable reproductive peak with copulation in autumn-winter. Moreover, histological examination demonstrated that the ovaries of this member of the family Bythitidae had a 'group-synchronous' pattern. No spermatophores in males and embryos in females were observed in the histological sections analysed

Emigración y retención de Palinurus elephas (Fabricius, 1787) en un área marina protegida del Mediterráneo central occidental

This study describes the results obtained by applying the Arnason Schwartz multistate mark-recapture model to eight years of data collected in and around a small no-fishing marine protected area (MPA; 4 km2) in the central western Mediterranean. From 1997 to 2004, a total of 4044 specimens of Palinurus elephas (Fabr., 1787) were tagged and 317 recaptured. The most parsimonious model which best explained the data variability was that of a temporally constant rate of apparent survival and movement in each of the two strata. The absence of any temporal influence in the apparent survival rate inside the no-take area suggested that spillover and mortality are constant for each period of the study. The lower apparent survival rate in surrounding zones than inside the MPA (0.26 ± 0.04 (SE) vs 0.94 ± 0.03 (SE)) is presumed to be a function of fishing effort. A continuous movement of P. elephas across the boundary of the small MPA was also tested. This information on retention of lobsters in the MPA contributes to our understanding of the effect of introducing MPAs into a managed commercial fishery system.Este estudio presenta los resultados de aplicar el modelo multiestado de marcado y recaptura de Arnason Schwartz a una serie de ocho años de datos recolectados en el interior y alrededor de una pequeña área marina protegida (AMP) vedada a la pesca (4 km2) del Mediterráneo central occidental. Desde 1997 a 2004, un total de 4044 ejemplares de Palinurus elephas (Fabr., 1787) fueron marcados, de los cuales 317 fueron recapturados. El modelo más parsimonioso que explicó mejor la variabilidad de los datos fue aquel con una tasa temporal constante de aparente supervivencia y movimiento entre los dos estratos. La ausencia de influencia temporal sobre la tasa de supervivencia aparente en el interior del área protegida, sugirió que el “spillover” y la mortalidad son constantes para cada periodo del estudio. La menor tasa aparente de supervivencia en zonas alrededor de la reserva respecto al interior de la misma (0.26 ± 0.04 (SE) vs 0.94 ± 0.03 (SE)) se considera que es una función del esfuerzo pesquero. Un movimiento continuo de P. elephas a través de los límites de la pequeña AMP fue evaluado. Esta información sobre la retención de langostas en el AMP contribuye a comprender el efecto de la introducción de AMPs en un sistema regulado de pesquería comercial

Emigration and retention of <i>Palinurus elephas</i> (Fabricius, 1787) in a central western Mediterranean marine protected area

Este estudio presenta los resultados de aplicar el modelo multiestado de marcado y recaptura de Arnason Schwartz a una serie de ocho años de datos recolectados en el interior y alrededor de una pequeña área marina protegida (AMP) vedada a la pesca (4 km2) del Mediterráneo central occidental. Desde 1997 a 2004, un total de 4044 ejemplares de Palinurus elephas (Fabr., 1787) fueron marcados, de los cuales 317 fueron recapturados. El modelo más parsimonioso que explicó mejor la variabilidad de los datos fue aquel con una tasa temporal constante de aparente supervivencia y movimiento entre los dos estratos. La ausencia de influencia temporal sobre la tasa de supervivencia aparente en el interior del área protegida, sugirió que el "spillover" y la mortalidad son constantes para cada periodo del estudio. La menor tasa aparente de supervivencia en zonas alrededor de la reserva respecto al interior de la misma (0.26 ± 0.04 (SE) vs 0.94 ± 0.03 (SE)) se considera que es una función del esfuerzo pesquero. Un movimiento continuo de P. elephas a través de los límites de la pequeña AMP fue evaluado. Esta información sobre la retención de langostas en el AMP contribuye a comprender el efecto de la introducción de AMPs en un sistema regulado de pesquería comercial

Pautas de movimiento de la langosta Palinurus elephas (Fabricius, 1787) desde un área protegida en el Mediterráneo occidental central

Movement patterns of the spiny lobster Palinurus elephas were determined from 389 individuals (total tagged 5666) tag-recaptured inside a no-take area of the central western Mediterranean and its surrounding zone. High site association and limited movements in tagged lobsters was observed; 60.4% of lobsters moved less than 2 km from the centre of the area (site of release). No clear relationship between lobster movement pattern and sex or size was observed; however, it seemed that the largest males and females tended to be more resident, thus contributing to the rebuilding of the biomass of local lobsters. Most lobsters undertook migrations in the southwest direction. The increased availability of shelters and food towards the southwest could have contributed to the lobsters’ movement. The results of our research indicate that the small size of the protected area and the scale of the movement exhibited by tagged lobsters allows a proportion of the lobster population to move out of the protected area and become susceptible to capture in the adjacent fishery.Se determinaron las pautas de movimiento de 389 individuos de la langosta Palinurus elephas (total marcados 5666) marcados y recapturados en el interior de un área protegida (sin captura) así como de su área circundante. En las langostas marcadas se observó una elevada asociación al lugar de liberación, así como movimientos limitados: el 60.4% de las langostas se movieron menos de 2 km desde el centro del área de liberación. No se observó ninguna clara relación entre las pautas de movimiento de las langostas y su sexo y talla; no obstante, hay una tendencia a que los machos y hembras grandes muestren un comportamiento más residente, contribuyendo así al aumento de la biomasa local. La mayor parte de langostas mostró migraciones en dirección sudoeste. La mayor disponibilidad de refugios y alimento hacia el sudoeste pudo haber contribuído al movimiento de las langostas. Los resultados de este estudio indican que el pequeño tamaño del área protegida y la escala de movimientos mostrados por las langostas marcadas permite a una porción de la población su salida del área protegida y su susceptibilidad a la captura en la pesquería adyacente

Movement patterns of the spiny lobster <em>Palinurus elephas</em> (Fabricius, 1787) from a central western Mediterranean protected area

Movement patterns of the spiny lobster Palinurus elephas were determined from 389 individuals (total tagged 5666) tag-recaptured inside a no-take area of the central western Mediterranean and its surrounding zone. High site association and limited movements in tagged lobsters was observed; 60.4% of lobsters moved less than 2 km from the centre of the area (site of release). No clear relationship between lobster movement pattern and sex or size was observed; however, it seemed that the largest males and females tended to be more resident, thus contributing to the rebuilding of the biomass of local lobsters. Most lobsters undertook migrations in the southwest direction. The increased availability of shelters and food towards the southwest could have contributed to the lobsters' movement. The results of our research indicate that the small size of the protected area and the scale of the movement exhibited by tagged lobsters allows a proportion of the lobster population to move out of the protected area and become susceptible to capture in the adjacent fishery

New insights upon the reproductive biology of the sea cucumber Holothuria tubulosa (Echinodermata, Holothuroidea) in the Mediterranean: Implications for management and domestication

Holothuria tubulosa is one of the most common sea cucumber species inhabiting the Mediterranean Sea. Due to its commercial interest for the international market, it has been harvested without proper management causing the overexploitation of its stocks. Inadequate management is also caused by lack of information on basic biology and ecology not allowing the estimating of the species vulnerability and resilience to growing anthropogenic pressures. In this paper, we have investigated basic life-history traits of H. tubulosa (population structure and reproductive cycle) in a population of Central-Western Mediterranean (Sardinia, Italy). A macroscopic maturity scale for both sexes was defined through an instrumental colorimetric analysis of the gonads and the ramification level of the gonad’s tubules, subsequently confirmed by histological analysis. The seasonal trend of the Gonado Somatic Index, the changes in color of the gonads and tubules ramification indicated that the spawning period of H. tubulosa was concentrated in summer with a peak in late August, closely related to the increase in water temperature. A synchronous development of the gonads, with a unique and short reproductive event during the year, was also detected. In conclusion, this study provides new evidence on the biological and ecological features of H. tubulosa, essential data for developing a scientifically-based stock assessment as well as conservative management at a local scale. Finally, we provided basic information for the domestication of broodstock in a conservative hatchery

Onboard Scientific Observers Provide a Realistic Picture of Harvesting and Management Priorities for the Precious Red Coral (Corallium rubrum L.)

Mediterranean red coral Corallium rubrum is considered the most precious coral worldwide. Harvesting activities are performed by licensed scuba divers and managed through the recent pan-Mediterranean management plan issued by General Fisheries Commission for the Mediterranean (GFCM) along with measures locally enacted, imposing limits on licenses, harvesting season, minimum depth of dive, and size. The use of Remotely Operated Vehicles (ROVs) is prohibited, with the only exception being for scientific purposes. Despite measures already in force, the implementation of additional management tools has been recently recommended. This article reports results from the first monitoring campaign on C. rubrum harvesting based on ROVs for seabed exploration and Onboard Scientific Observers (OSOs), carried out from 2012 to 2015 along the coast of Sardinia (Mediterranean Sea—Western basin). More than 450 dives were monitored, confirming how ROV's support eases the scouting of exploitable banks, leading to increases in catches. OSOs reported the collection of colonies below the minimum reference size and catches/dive above limits. Onboard observers collected data also on colony diameter, which is crucial for the estimation of population size structure and exploitation status. OSOs proved to be valid tools in providing additional and reliable information on red coral harvesting, thus deserving to be included among mandatory measures for the sustainable exploitation of red coral in the Mediterranean Sea