Journal of Experimental Marine Biology and Ecology (J EXP MAR BIOL ECOL)

Publications in this journal

• Article: Consumption rates and digestibility of four food items by the marine gastropod Charonia seguenzae (Aradas & Benoit, 1870)

  Chrisa K. Doxa, Pascal Divanach, Maroudio Kentouri
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  ABSTRACT: Consumption and digestibility rates of four food items (sea star: Luidia sarcii and Astropecten aranciacus, squid: Nototodarus sloanii, shrimp: Parapenaeus longirostris and fish: Boops boops) by the marine gastropod Charonia seguenzae were studied. The food with the greatest mean daily consumption in wet weight was the sea star with 24.03 ± 2.69 g, followed by fish (11.36 ± 3.74 g), shrimp (9.52 ± 1.21 g) and squid (7.36 ± 2.16 g). Absorption rate was higher when squid was consumed (97.1 ± 3.7%, dry weight) followed by shrimp (93.5 ± 4%), fish (87.8 ± 8.6%) and sea star (45 ± 15.3%). Although squid absorption was higher, due to high consumption rates against sea star and fish, energy input did not differ significantly. Tritons absorbed a large proportion of ash only when consuming sea star. Results indicate that C. seguenzae can adapt well in captivity conditions by efficiently digesting alternative foods. Furthermore, a low metabolism is indicated by its low transit that needs 6 to 8 days to digest food consumed from a single feeding.
  Journal of Experimental Marine Biology and Ecology 08/2013; 446:10-16.
• Article: Biomechanical response of two fast-growing tropical seagrass species subjected to in situ shading and sediment fertilization

  Yayu A. La Nafie, Carmen B. de los Santos, Fernando G. Brun, Marieke M. van Katwijk, Tjeerd J. Bouma
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  ABSTRACT: Although seagrasses experience strong hydrodynamic forces, little is known about their biomechanical response in spite of the potential importance for their ecological success. We investigated how light reduction and sediment-nutrient enrichment affect biomechanical and morphological properties of two short-lived tropical seagrass species: Halophila ovalis and Halodule uninervis. A 50-day manipulative field experiment of shading and sediment-nutrient enrichment versus a natural population (control) showed that both shading and nutrient enrichment made the leaves of Halophila ovalis weaker (lower FTS) and more elastic (lower ET). As the absolute breakability of leaves (FMAX) was not affected by either of the treatments, this implies that these changes in strength and stiffness resulted from the increase in leaf dimensions under nutrient enrichment (i.e., longer, wider and thicker leaves) and shading conditions (i.e., thicker leaves). In contrast, the biomechanical properties of H. uninervis leaves were less responsive and only became more extensible under shading whilst their biomechanics did not change under sediment nutrient enrichment. This limited response of H. uninervis might be due to the lack of morphological response in this species since leaves only became longer under nutrient enrichment. When comparing both species across treatments under shading (after normalizing them with their controls), H. ovalis became significantly weaker compared to H. uninervis, and the latter became more extensible. Under nutrient enrichment, H. ovalis became significantly more elastic compared H. uninervis. Overall we found that (i) biomechanical properties can be affected by environmental conditions, (ii) the responses were species specific, and (iii) seagrass morphology (leaf thickness and width) affected by environmental conditions will influence seagrass biomechanical properties. Further experimental studies on seagrass biomechanics are needed as present understandings of the acclimation of these properties and the consequences for species functioning are only starting to emerge.
  Journal of Experimental Marine Biology and Ecology 05/2013; IN PRESS.
• Article: The ranging patterns of female bottlenose dolphins with respect to reproductive status: Testing the concept of nursery areas

  Q.A. Gibson, E.M. Howells, J.D. Lambert, M.M. Mazzoil, J.P. Richmond
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  ABSTRACT: Adult female bottlenose dolphins (Tursiops truncatus) form fission–fusion social networks and adjust their association patterns with respect to their reproductive status. It is commonly reported that mothers with dependent calves preferentially utilize ‘nursery areas’ consisting of protected, shallow water habitats. However, few studies have tested whether females adjust their ranging patterns based on their reproductive status. Using photo-identification data from the Indian River Lagoon, Florida (1997–2007), we conducted both longitudinal and cross-sectional analyses to compare the ranging patterns of adult females with calves versus females without calves. The size of females' home ranges (HR) and core areas (CA) were not significantly different between reproductive states (P > 0.05), presumably due to a lack of directional pattern in the relative sizes of female's home ranges when with a calf and without a calf. HR size varied greatly among individual females, 9.37–190.83 km2 for females with a calf (x ± SE = 76.50 ± 10.20 km2) versus 20.90–186.13 km2 for the same females without a calf (97.00 ± 11.50 km2). CA size ranged from 0.35 to 56.75 km2 for females with calves (14.62 ± 3.60 km2) and 0.39 to 49.72 km2 for females without calves (20.01 ± 3.60 km2). Overlap between females' ranges with calf and without calf also varied greatly among individuals (HR: 13.92–94.97%, CA: 0–93.97%). On average, females with calves continued to utilize 51.98 ± 5.08% of their without calf HR but only 19.09 ± 5.45% of their without calf CA. In our cross-sectional analyses, a large percentage (65.55 ± 3.36%) of the 95% utilization distribution for females without calves was also used by females with calves across all seasons. However, overlap between the 50% utilization distributions of females with calves and females without calves was low (<11%) in all seasons, especially autumn. These findings suggest that variation in ranging patterns among individual females was greater than by reproductive state. Females continued to use a large proportion of their overall range, but concentrated in different areas depending on their reproductive status.
  Journal of Experimental Marine Biology and Ecology 05/2013; 445:53-60.
• Article: Pre-breeding ecophysiology of a long-distance migratory seabird

  Rosana Arizmendi-Mejía, Teresa Militão, Ginés Viscor, Jacob González-Solís
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  ABSTRACT: The energetic demands of animals change throughout their annual life cycle. In migrating birds, reproduction and migration are the two most energy demanding processes; the transition from one to the other require a number of physiological adjustments. When arriving to the breeding grounds, long-distance migratory birds need to recover from migration and prepare for reproduction. This process is crucial, since pre-breeding body condition has been established as a critical factor influencing reproductive success in several avian species. In the present study we examined the physiological condition of the Cory's shearwater (Calonectris diomedea borealis, Cory 1881) after arrival from migration to a breeding colony, as well as its changes throughout the pre-laying period. We weighed and took blood samples from 149 shearwaters newly arrived to their breeding colony. If birds were found again after 10, 20, 30 or 40 days since their first capture, they were resampled. We examined individual variation of biochemical parameters, body mass and blood oxygen transport capacity in both males and females. Our results indicate that birds were improving their body condition after arrival from migration. Plasma metabolites revealed shearwaters were depositing fat and degrading muscular mass during post-migration and pre-laying, suggesting shearwaters were remodeling their body composition to have more space for lipid reserves. Females started fat deposition earlier than males, probably to cope with the lipid demands of egg formation. This study shows that biochemical blood parameters are good indicators of the ecophysiological changes experienced by post-migrating and pre-breeding birds.
  Journal of Experimental Marine Biology and Ecology 05/2013; 443:162-168.
• Article: Multiple paternity in leopard shark (Triakis semifasciata) litters sampled from a predominantly female aggregation in La Jolla, California, USA

  A.P. Nosal, E.A. Lewallen, R.S. Burton
  Journal of Experimental Marine Biology and Ecology 05/2013; 446:110-114.
• Article: Performing fish counts with a wide-angle camera, a promising approach reducing divers' limitations

  J. Assis, B. Claro, A. Ramos, J. Boavida, E.A. Serrão
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  ABSTRACT: Visual standardised methods for census of reef fishes have long been used in fisheries management and biolog- ical surveys. However, these tools have inherent sources of bias and the SCUBA divers who perform them are highly constrained in terms of survey time, maximum depth and frequency of sampling. Alternatives like under- water video are thus being recommended in a wide range of configurations. Yet, all these techniques are still limited in field of view, particularly when compared to the ability of a SCUBA diver performing censuses. In this scope, we evaluated the potential of an underwater wide-angle camera (UWC) to survey fish assemblages by testing it against instantaneous underwater visual census (UVC). Our results showed minimal yet significant differences between methods, mainly because of the camera's loss of resolution when under extreme visibility conditions. Both approaches had the same consistency and ability to detect changes in fish assemblages but, to estimate total species richness, the UWC needed less field effort. Moreover, a SCUBA diver performing census had an effect on fish assemblages which introduced differences of greater magnitude than those found between methods. The removal of the diver effect, the proven ability to detect changes in fish assemblages and the verified gain in field effort, pointed the wide-angle camera as a promising tool to perform census of reef fishes.
  Journal of Experimental Marine Biology and Ecology 04/2013; 445:93–98.
• Article: The tolerance to desiccation of the submerged macrophytes Ruppia cirrhosa Petagna (Grande) and Zostera capensis Setchell.

  Janine B Adams, Bate GC
  Journal of Experimental Marine Biology and Ecology 02/2013; 183:53 - 62.
• Article: Patterns of macromolecular synthesis by natural phytoplankton assemblages under changing upwelling regimes: In situ observations and microcosms experiments

  Marañón, E. Fernández, R. Anadón
  Journal of Experimental Marine Biology and Ecology 02/2013;
• Article: Osmotic effect of choline and glycine betaine on the gills and hepatopancreas of the Chasmagnathus granulata crab submitted to hyperosmotic stress.

  Matheus Parmegiani Jahn, Gabriela Maura Cavagni, Danielle Kaiser de Souza, Luiz Carlos Kucharski
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  ABSTRACT: Choline is the precursor of glycine betaine, a compatible osmolyte that can maintain the osmotic balance of cells in high osmolality media. This study examined the effect of hyperosmotic stress on the 14C-choline uptake in the hepatopancreas and gills of Chasmagnathus granulata crabs. Uptake in the hepatopancreas was influenced by different sodium concentrations in the incubation media. A reduction of uptake was observed in the hepatopancreas, anterior and posterior gills, in the presence of increasing concentrations of non-radioactive choline. There was a reduction of choline uptake in the anterior and posterior gills of animals submitted to long-term (72 h) hyperosmotic stress compared to the control group. The hepatopancreas incubated with 14C-choline during long-term hyperosmotic stress presented choline uptake values approximately two times higher than in the control group. The glycine betaine synthesis of this group was higher than the control group. These results demonstrate the osmotic effect of glycine betaine in crabs during hyperosmotic stress, and this effect was only observed in the hepatopancreas, and during the long-term 72-h stress. This paper shows, for the first time, the effect of choline and glycine betaine in the osmoregulatory process in crustaceans.
  Journal of Experimental Marine Biology and Ecology 02/2013; 334(00):1-9.