Spatio-temporal variability in the cannibalistic behaviour of European hake Merluccius merluccius: the influence of recruit abundance and prey availability.

Cannibalistic behaviour of European hake Merluccius merluccius was studied through the analysis of 49 836 gut contents belonging to individuals from 6 to 82 cm in total length (L(T)). Samples were collected every autumn between 1993 and 2009. The results showed that the consumption of conspecific individuals was consistent over space and time. The abundance, spatial distribution patterns and L(T) structure of M. merluccius recruits were the main variables involved in M. merluccius cannibalism. A geographical pattern was found since increasing cannibalism was observed in areas of recruit aggregations. The L(T) spectrum of recruits in autumn was also a key factor and dependent on the spawning period. When adults spawned from late spring to summer, an increasing cannibalism trend was found in autumn, due to the ideal size structure of the prey (M. merluccius recruits) for predators. Depth was also a significant variable, and a cannibal peak was detected at depths ranging between 50 and 200 m, coinciding with a spatial overlap of predator (pre-adults) and prey (recruits). The cannibalistic behaviour of M. merluccius began at c. 12 cm, although 75% were mid-sized individuals between 16 and 30 cm. Additionally, 90% of prey-hake were recruits <18·5 cm. Some biological and ecological aspects such as growth rate, spawning period, predation and competition interactions and the effect of some oceanographic events on M. merluccius cannibalism are also discussed.

Metazoan parasite communities and diet of the velvet belly lantern shark Etmopterus spinax (Squaliformes: Etmopteridae): a comparison of two deep-sea ecosystems.

By combining an examination of stomach contents yielding a snapshot of the most recent trophic niche and the structure of parasite communities reflecting a long-term feeding niche, this study aimed at gaining more comprehensive information on the role of the small-sized deep-water velvet belly lantern shark Etmopterus spinax in the local food webs of the Galicia Bank and the canyon and valley system of the Avilés Canyon, which have been both proposed for inclusion in the Natura 2000 network of protected areas. As far as is known, this study provides the first comparative parasite infracommunity data for a deep-sea shark species. Component parasite communities in E. spinax were relatively rich, whereas the infracommunities were rather depauperate, with similar low diversity at both localities. The significant differences in the composition and structure of both parasite communities and prey assemblages indicate differential effects of the two deep-sea ecosystems on both long-term and most recent trophic niches of E. spinax. These results underline the importance of the use of multivariate analyses for the assessment of geographical variation in shark populations based on parasites and diet data.

Resource utilization by deep-sea sharks at the Le Danois Bank, Cantabrian Sea, north-east Atlantic Ocean.

The feeding habits of birdbeak dogfish Deania calcea, velvet belly lantern shark Etmopterus spinax and blackmouth catshark Galeus melastomus at Le Danois Bank, Cantabrian Sea, south Bay of Biscay were studied in relation to their bathymetric distribution. Deep-sea sharks were collected during two multidisciplinary surveys carried out in October 2003 and April 2004 at the Le Danois Bank. Two different habitats were defined: (1) the top of the bank, ranging from 454 to 642 m depth and covered by fine-sand sediments with a low percentage of organic matter, and (2) the inner basin located between the bank and the Cantabrian Sea's continental shelf, at depths of 810-1048 m, which was characterized by a high proportion of silt and organic matter. Deania calcea was not present at the top of the bank but was abundant below 642 m, while E. spinax was abundant in the shallower top of the bank but was not found in the deeper inner basin. There was almost no bathymetric overlap between these two deep-sea shark species. Galeus melastomus was found over the whole depth range. There seemed to be an ontogenetic segregation with depth for this species, however, since 80% of the specimens collected at the top of the bank were < 600 mm total length (L(T)) (mean 510 mm L(T)), whereas larger individuals (mean 620 mm L(T)) inhabited deeper zones. Galeus melastomus exhibited a significantly higher feeding intensity than both E. spinax at the top of the bank and D. calcea in the inner basin. Little dietary overlap between D. calcea and G. melastomus in the inner basin was found, with D. calcea being an ichthyophagous predator while the diet of G. melastomus at these depths was composed of a variety of meso-bathypelagic shrimps (e.g. Acantephyra pelagica, Pasiphaea spp. and Sergia robusta), cephalopods and fishes. The diets of E. spinax and G. melastomus at the top of the bank showed a high dietary overlap of euphausiids, which represented the main prey taxa for both species. Euphausiids declined in abundance with depth which was reflected in the diet of G. melastomus. The cluster analysis of prey affinities among hauls depicted two major groups, corresponding to the two different habitats (top of the bank and inner basin). Redundancy analysis also indicated top-basin segregation, with euphausiids representing the main prey taxa at the top of the bank and bathypelagic shrimps in the inner basin. Euphausiids and Micromesistius poutassou were key prey within the Le Danois Bank ecosystem since they were positively selected by the three deep-sea shark species. These results show that the feeding ecology of these predators in Le Danois Bank ecosystem is highly influenced by depth-related variables, as a result of changes in prey availability. Overall results were analysed in relation to the deep-sea Le Danois ecosystem structure and functioning.

Monitoring the Prestige oil spill impacts on some key species of the Northern Iberian shelf.

Selected key components of the continental shelf benthic and demersal communities were monitored for the two years following the Prestige oil spill (POS) in order to identify the possible ecological effects of the oil. This work includes the first results regarding changes in abundance, distribution and food habits of hake (Merluccius merluccius), four-spot megrim (Lepidorhombus boscii), Norway lobster (Nephrops norvegicus) and Pandalid shrimp (Plesionika heterocarpus) populations of Galician and Cantabrian Sea shelves following the POS. Significant reductions in the abundance of Norway lobster, Plesionika heterocarpus and four-spot megrim were detected in the POS maximum impact area, located over the Galician shelf. Noteworthy recoveries were observed in the 2004 abundance indices of four-spot megrim and Plesionika. On the other hand, no significant effects were detected in the abundance or distribution of hake juveniles even though the tar aggregates were bound by the same oceanographic drift events as the hake recruits were during the winter of 2003 (Navidad current) in different water column layers of the Cantabrian Sea. Feeding patterns of the four species analysed did not present apparent modifications that can be related to the POS.

[Swallowing changes in cerebrovascular accidents: incidence, natural history, and repercussions on the nutritional status, morbidity, and mortality]. / Alteraciones de la deglución en el accidente cerebrovascular: incidencia, historia natural y repercusiones sobre el estado nutricional, la morbilidad y la mortalidad.

OBJECTIVE: To determine the frequency of dysphagia in CVA, its natural history and value as a risk factor of respiratory infection, malnutrition and death. PATIENTS AND METHODS: A prospective study was made of 187 consecutive patients with cerebrovascular accidents (CVA). A standardized test for dysphagia was done during the first two days of the illness and repeated three days a week. The levels of urea, total proteins and albumin were determined on admission and on discharge. The patients were questioned by phone after 6 months. RESULTS: There was dysphagia of liquids in 36.4% of the patients. The incidence of dysphagia for semisolids was of the same frequency but more severe. Coma was the cause of inability to swallow in 25.7% of the patients. During their stay in hospital one third of the patients with dysphagia died, one third became normal and one third still had dysphagia when they were discharged. After one week, one, three and six months respectively, the cure rate for dysphagia was 29.4%, 4.1%, 55.9% and 55.9%, and survival 83.8%, 67.6%, 61.8% and 60.3%. Thus after 6 months only 3 patients (4.4%) were alive and dysphagic. Half of the 'cures' occurred in the first week, and none occurred after more than 77 days. As compared to the non-dysphagic patients, the dysphagic patients had 10 times more risk of respiratory infection, 18 times higher risk of death, greater loss of albumin and less loss of urea. CONCLUSIONS: There is a high prevalence of dysphagia in CVA and although functional prognosis is not unfavorable, respiratory infections, malnutrition and death are frequent.