Burying behaviour in the bobtail squid Sepiola atlantica (Cephalopoda: Sepiolidae)

5 páginas, 1 figura, 1 tablaThe burying behavioural pattern of the small Atlantic bobtail squid (Sepiola atlantica) in natural substrate is described, quantitatively differentiating the movements in different phases and the chromatic changes associated with this behaviour. All specimens showed the same two-part sequence of burying, which triggered a display of colour changes peculiar to this species. Our results suggested that this was a consistent behaviour during burial. The mean latency time in the alert posture was 9.55 ± 5.49 s. The mean duration of the first phase was 12.2 ± 4.37 s. The mean duration of the second phase was 10.2 ± 2.95 s. The average time spent completing the behavioural pattern was 21.9 ± 4.93 s. Burying time was not related to size. Differences observed between individuals were associated with the number of movements in each phase. However, these movements were not significantly related to the size of the animals. A comparison of the burying pattern of this species with other members of the family Sepiolidae is madePeer reviewe

Für ein Ende des NATO-Krieges und eine politisch-diplomatische Regelung in Afghanistan

Four visual censuses targeting Octopus vulgaris living in dens on sandy bottoms were carried out from June to October 2013 in the National Park of the Atlantic Galician Islands (NW Spain). Censuses were undertaken by scuba diving between 5 and 21 m depth in daytime. The total area swept was 13.75 ha. There were no significant differences between octopus presence in dens during open and closed fishing seasons. Depth had a significant negative relationship with occupancy. The average number of dens per 1000 m2 was 3.84±0.84 in June and 3.89 in October. The area per den was 260 m2. Den number estimations varied between 1586 and 2057. The largest number of dens (76.5%) was found between 5 and 10 m depth. Den distribution was clumped. No significant differences were found between octopus size classes (small, medium and large) and den diameter. Associate dens were observed. There were no significant differences in den diameter and shell types found around the middens. Many dens could be “permanent”. Drilling bivalve shell behaviour is discussed. The surveyed area had around 1100 individuals, mainly small specimens. No significant differences were found between octopus size and depth. Substrate, den type and food abundance and availability (especially razors Ensis arcuatus) seem to be the main factors influencing dens and octopus density and distribution. Den availability does not appear to be a limiting factor in this case. Temperature, den availability, predators and fishing pressure influencing density and distribution are discussed. Rodas inlet may be a preferential habitat for O. vulgaris individuals ranging from 200 to 2000 g, but especially small specimens ( ≤ 1000 g)

Identification and characterization of esential habitats for three cephalopod species in the national parks of Galician Atlantic Islands and Cabrera

31 pages, 16 figures, 8 tables, 1 appendix[EN] We evaluated specific habitat features (bottom substrate type, depth, temperature and season) at random locations in the Cíes archipelago (Galician Atlantic Islands National Park, NW Spain) and to determine their impact on Octopus vulgaris, Sepia officinalis and Loligo vulgaris habitat use. We performed 113 underwater visual transects by scuba diving between April 2012 and August 2015. Habitat features were evaluated as predictors of the presence/absence of spawning dens and egg clusters using Generalized Additive Models. The O. vulgaris spawning essential habitats was found between 5 and 30 m depth in rocky bottoms from Punta Escodelo to Punta Ferreiro (Monteagudo Island), which surface is 6% of the total marine area of the Cíes islands. We propose a complete protection of this area for exploitation. underwater visual transects also showed that there is an O. vulgaris hatchery essential habitat (specimens ≤1000 g) in the sandy bottoms of the Rodas inlet. This small area (2.8% of the total) could be also protected. S. officinalis results revealed two SEH: Bajo de Viños and Piedra del Borrón, hard bottom shoals between 8-13 m covered by sea fans and sea worms and located in the central Cíes islands. We also suggest protecting that small area (0.28% of the total). Very few L. vulgaris eggs masses were found with underwater visual transects and artificial devices attractors in the Cíes islands. Also very few specimens of O. vulgaris and S. officinalis were found with underwater visual transects in Cabrera National Park between 5 and 50 m depth. Two squid spawning essential habitats were located in that park using artificial devices attractors: Na Redona and Ses Rates, both on sandy bottoms from 18 to 50 m depth with fast marine currents. The spawning essential habitats found reveal indicators of three species habitat selection and should help to identify targets for habitat improvement projects and ecosystem management approaches[ES] Mediante 112 censos visuales con escafandra autónoma realizados entre abril de 2012 y agosto de 2015, distribuidos aleatoriamente en el archipiélago de Cíes (Parque Nacional de las Islas Atlánticas de Galicia), se evaluaron las características (tipo de sustrato, profundidad, temperatura y estación) de los hábitats esenciales de Octopus vulgaris, Sepia officinalis y Loligo vulgaris. Dichas características se emplearon como predictores de la presencia/ausencia de guaridas de desove o masas de huevos utilizando Modelos Aditivos Generalizados. El hábitat esencial para el desove de O. vulgaris se localizó entre 5 y 30 m de profundidad en fondos rocosos entre Punta Escodelo y Punta Ferreiro (isla de Monteagudo), cuya superficie es del 6% del total. Proponemos su protección completa para la explotación. Los censos visuales con escafandra autónoma mostraron un hábitat esencial de cría de O. vulgaris en fondos arenosos de la ensenada de Rodas. Esta pequeña área (2,8% del total) podría ser también protegida. Los resultados para S. officinalis revelaron dos HE para el desove: el Bajo de Viños y la Piedra del Borrón, bancos de fondo duro entre 8-13 m cubiertos por gorgonias y poliquetos tubícolas en la ensenada de Rodas. Se sugiere protección para este área (0,28% del total). Apenas se hallaron puestas de L. vulgaris con censos visuales con escafandra autónoma y Dispositivos Atractores de Puesta en Cíes. También se observaron muy escasos ejemplares de S. officinalis y O. vulgaris con censos visuales con escafandra autónoma entre 5 y 50 m de profundidad en el Parque Nacional de Cabrera. Se identificaron dos HE para el desove del calamar en el Parque Nacional de Cabrera usando Dispositivos Atractores de Puesta: Na Redona y Ses Rates, fondos arenosos entre 18 y 50 m de profundidad con rápidas corrientes. Estos HEs son indicadores de selección del hábitat, y constituyen un notable apoyo para identificar objetivos en proyectos de conservación de hábitats y enfoques ecosistémicos en la gestión pesqueraMiguel Cabanellas-Reboredo fue becado por la Conselleria de Educació del Govern de les Illes Balears (Fondo Social Europeo) y actualmente beneficiario de contrato post-doctoral Juan de la Cierva formación (MINECO). Marta Sestelo disfrutó de beca de investigación SFRH/BPD/93928 de Fundacão Ciência e Tecnologia de Portugal y de proyectos del Ministerio de Ciencia e Innovación y la Xunta de Galicia. Este proyecto estuvo financiado por el Organismo Autónomo de Parques Nacionales del Ministerio de Agricultura, Alimentación y Medio Ambiente (CEFAPARQUES, Proyecto número: 458/2011)N

Spawning strategy in Atlantic bobtail squid Sepiola atlantica (Cephalopoda: Sepiolidae)

Abstract This study aimed to determine the spawning strategy in the Atlantic bobtail squid Sepiola atlantica, in order to add new information to the knowledge of its reproductive strategy. A total of 12 females that spawned in aquaria were examined. Characteristics of the reproductive traits and egg clutches were similar to those of other known Sepiolidae. Clutch size varied from 31 up to 115 eggs. Females of this species had incorporated up to 1.58 times of their body weight into laid eggs. The size of laid eggs showed a positive correlation with maternal body size, supporting the idea that female size is a determinant of egg size. Our data suggest that S. atlantica is an intermittent terminal spawner, and that its spawning strategy comprises group-synchronous ovary maturation, multiple egg laying, and deposition of egg clutches in diVerent locations. The obtained data provide insights for future comparative studies on reproductive allocation.Peer reviewe

Mating behavior of the Atlantic bobtail squid sepiola atlantica (Cephalopoda: sepiolidae)

5 páginas, 1 figura, 1 tablaThe mating behavioral pattern of the bobtail squid (Sepiola atlantica) was observed and described for the first time in laboratory conditions. A total of five matings were recorded. No courtship was noted in any of the mating events. In all the cases, the male moved quickly towards the female holding her by the middle of the ventral region of the mantle with his arms. The male, situated below the female, introduced his dorsal arms (the left dorsal arm is hectocotylized and passes the spermatophores) into the mantle cavity of the female, while grasping her by the ventral region with his laterodorsal arms and by the neck with his lateroventral arms, sometimes introducing them into the female’s mantle cavity. The male showed the same pattern of coloration during the entire mating process, whereas the female changed slowly and successively her chromatic pattern. The duration of the mating varied between 68 and 80 minutes. A comparison of the mating pattern of this species with other members of the family Sepiolidae is madeThe first author was supported by a scholarship from the Secretaría Xeral de Inmigración de la Xunta de Galicia.Peer reviewe

Unidad de Monitorización y Observación del Medio Marino: ¿Qué servicios ofrecemos?

Poster.-- Encontros IIM 4ª fase, Vigo, 24 novembro 2023N

Xenostrobus securis (Lamarck, 1819) (Mollusca: Bivalvia): first report of an introduced species in Galician waters

6 páginas, 2 figuras.-- The final publication is available at www.springerlink.comThe presence of the non-indigenous species, the black-pygmy mussel Xenostrobus securis, is reported here for the first time in an intense shellfish farming area off Galicia (NW Spain). Very high concentrations of this mytilid bivalve have colonized estuarine waters located at the inner part of the Ria de Vigo. The invasive role of X. securis is discussed in the context of the wide ecological tolerance of the species and the recent finding of settlements of this species on numerous colonies of the economically-important blue mussel Mytilus galloprovincialis. The mode of introduction of the black-pygmy mussel is also discussed in relation to human management activities.Peer reviewe

First report of Anisakis simplex (Nematoda, Anisakidae) in the sea lamprey (Petromyzon marinus)

6 páginas, 5 figuras, 2 tablasA total of 64 sea lampreys Petromyzon marinus caught in Galician rivers in 2012 (NW Spain), were dissected and examined for evaluate the presence of marine parasitic Anisakidae nematodes following microscopic and PCR analysis. The results revealed that sea lampreys are infected by third-larval stage of Anisakis simplex. Internal organs, especially the gonads, and flesh, hosted from 1 to 10 Anisakis larvae with prevalence values reaching up to 60%. This is the first time that this infection is registered in the sea lamprey. The plausible hypothesis is that sea lamprey might has acquired larvae once feeding on flesh or the products of tissue cytolysis from infected teleosts (e.g. Atlantic salmon). In Galician waters, the sea lamprey could act as a transport host for A. simplex from marine to freshwater ecosystems. This finding has epidemiological relevance considering the zoonotic and gastro-allergic condition of this parasite.Peer reviewe