Journal of Marine Biology The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Reef Fish Dispersal in the Hawaiian Archipelago: Comparative Phylogeography of Three Endemic Damselfishes Tue, 05 Apr 2016 13:34:46 +0000 Endemic marine species at remote oceanic islands provide opportunities to investigate the proposed correlation between range size and dispersal ability. Because these species have restricted geographic ranges, it is assumed that they have limited dispersal ability, which consequently would be reflected in high population genetic structure. To assess this relationship at a small scale and to determine if it may be related to specific reef fish families, here we employ a phylogeographic survey of three endemic Hawaiian damselfishes: Abudefduf abdominalis, Chromis ovalis, and Chromis verater. Data from mitochondrial markers cytochrome b and control region revealed low but significant genetic structure in all three species. Combining these results with data from a previous study on Dascyllus albisella and Stegastes marginatus, all five endemic damselfish species surveyed to date show evidence of genetic structure, in contrast with other widespread reef fish species that lack structure within the Hawaiian Archipelago. Though individual patterns of connectivity varied, these five species showed a trend of limited connectivity between the atolls and low-lying Northwestern Hawaiian Islands versus the montane Main Hawaiian Islands, indicating that, at least for damselfishes, the protected reefs of the uninhabited northwest will not replenish depleted reefs in the populated Main Hawaiian Islands. Kimberly A. Tenggardjaja, Brian W. Bowen, and Giacomo Bernardi Copyright © 2016 Kimberly A. Tenggardjaja et al. All rights reserved. Colorimetric Detection of Caspase 3 Activity and Reactive Oxygen Derivatives: Potential Early Indicators of Thermal Stress in Corals Thu, 03 Mar 2016 13:14:19 +0000 There is an urgent need to develop and implement rapid assessments of coral health to allow effective adaptive management in response to coastal development and global change. There is now increasing evidence that activation of caspase-dependent apoptosis plays a key role during coral bleaching and subsequent mortality. In this study, a “clinical” approach was used to assess coral health by measuring the activity of caspase 3 using a commercial kit. This method was first applied while inducing thermal bleaching in two coral species, Acropora millepora and Pocillopora damicornis. The latter species was then chosen to undergo further studies combining the detection of oxidative stress-related compounds (catalase activity and glutathione concentrations) as well as caspase activity during both stress and recovery phases. Zooxanthellae photosystem II (PSII) efficiency and cell density were measured in parallel to assess symbiont health. Our results demonstrate that the increased caspase 3 activity in the coral host could be detected before observing any significant decrease in the photochemical efficiency of PSII in the algal symbionts and/or their expulsion from the host. This study highlights the potential of host caspase 3 and reactive oxygen species scavenging activities as early indicators of stress in individual coral colonies. Mickael Ros, Mathieu Pernice, Sebastien Le Guillou, Martina A. Doblin, Verena Schrameyer, and Olivier Laczka Copyright © 2016 Mickael Ros et al. All rights reserved. Growth, Fatty Acid, and Lipid Composition of Marine Microalgae Skeletonema costatum Available in Bangladesh Coast: Consideration as Biodiesel Feedstock Mon, 29 Feb 2016 10:48:42 +0000 Among the various potential sources of renewable energy, biofuels are of most interest. Marine microalgae are the most promising oil sources for making biofuels, which can grow very rapidly and convert solar energy to chemical energy via CO2 fixation. The fatty acid profile of almost all the microalgal oil is suitable for the synthesis of biofuel. In this research, fatty acid and lipid contents of Bangladeshi strains of marine microalgae Skeletonema costatum were performed. For this, the crude oil was extracted by Soxhlet extraction method, using three most common solvent systems, pure hexane and mixture of CHCl3 : MeOH (2 : 1) and hexane : EtOH (3 : 1) one by one. Highest oil recovery (15.37%) came from CHCl3 : MeOH (2 : 1) solvent system from dry biomass whereas the lowest (2.49%) came from n-hexane from wet biomass. The qualitative analysis of the extracted oil by GC/MS analysis revealed that it contained significant amount of myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), and palmitoleic acid (C16:1). It also indicated presence of hexadecatrienoic acid, benzenedicarboxylic acid, oleic acid, arachidonic acid, eicosapentaenoic acid (EPA), 9-Octadecenoic acid methyl ester (C19H36O2), and so forth. The obtained fatty acid profile indicates high potentiality of S. costatum species to be used as promising biofuel feedstock a little improvisation and substantially it can replace diesel in near future. Tania Sharmin, Chowdhury Md. Monirul Hasan, Sheikh Aftabuddin, Md. Atiar Rahman, and Mala Khan Copyright © 2016 Tania Sharmin et al. All rights reserved. Food and Feeding Dynamics of Stolephorus commersonnii (Lacepede, 1803) (Family: Engraulidae) from South Andaman Thu, 19 Nov 2015 07:23:05 +0000 The feeding dynamics of Stolephorus commersonnii along the coastal waters of South Andaman during October, 2011, to September, 2012, were examined by employing “point’s method.” The results of the present study has shown that S. commersonnii mainly is a planktonivorous carnivore chiefly feeding in the pelagic realm on planktonic crustaceans, bivalves, gastropods, and miscellaneous food items. The copepods formed the main prey item, contributing their maximum during November 2011 (47.55%) and lowest in December (24.21%) which was confirmed by various food preference indices. There was no significant seasonal variation in the feeding preference. Lower length classes fed mainly on planktonic copepods and amphipods whereas the higher length classes fed mainly on postlarval shrimps and planktonic crustaceans like Lucifer sp. and Acetes sp. Feeding intensity was seasonal, but independent of the length of fish. Gastrosomatic index was highest during monsoon, indicating active feeding. During the period when a maximum percentage of fully mature individuals were present, the feeding intensity was found to be low. The trophic level of this species was found to be . M. Arun Kumar, G. Padmavati, and S. Venu Copyright © 2015 M. Arun Kumar et al. All rights reserved. Heavy Metals in Terapon puta (Cuvier, 1829) from Karachi Coasts, Pakistan Wed, 11 Nov 2015 06:26:08 +0000 This study was carried out to investigate the accumulation of Fe, Mn, Cd, Pb, and Ni in Terapon puta from Karachi Fish Harbor, Pakistan. There were no significant differences in the concentration of the metals except Mn in T. puta, which is obtained from the different seasons. The highest metal concentration is Fe followed by Mn. Cd, Pb, and Ni were measured relatively lower concentrations. The mean (± SD) Fe, Mn, Cd, Ni, and Pb levels in the muscles tissues of T. puta were , , , , and  mg/kg dry wt., respectively, whereas the mean (± SD) Fe, Mn, Cd, Ni, and Pb levels in the liver tissues of T. puta were , , , , and  mg/kg dry wt., respectively. Cd and Pb levels exceeded the Commission Regulation of European Union maximum limit of 0.05 mg/kg and 0.30 mg/kg, respectively. However, the results of Estimated Weekly Intake and Estimated Daily Intake indicate that the heavy metal levels in the samples are generally within respective recommended guidelines. Thus, it would appear from this study that the heavy metal levels in T. puta from Karachi coasts are low enough not to present a health hazard if the fish are consumed, although due attention should be paid to the maximum acceptable daily intake per kilogram body weight. Quratulan Ahmed, Levent Bat, and Farzana Yousuf Copyright © 2015 Quratulan Ahmed et al. All rights reserved. Trends in Marine Turtle Strandings along the East Queensland, Australia Coast, between 1996 and 2013 Mon, 09 Nov 2015 13:33:02 +0000 In-water monitoring of marine vertebrates is usually expensive while the use of stranding data can be used to provide a cost-effective estimation of disease and mortality. Strandings for Queensland are recorded in a web based database (StrandNet) managed by the Queensland Government’s Department of Environment and Heritage Protection (EHP). Data recorded in StrandNet from the east coast of Queensland between 1996 and 2013 were investigated for patterns of stranding. Significant trends in Queensland over this time were (i) an increase in the number of animals reported stranded within this study site; (ii) a species (loggerhead and green marine turtles) prevalence; (iii) a seasonal effect on different age classes stranding with most overall strandings occurring between August and November; and (iv) stranding hotspots (Moreton Bay, Hervey Bay, Rockhampton region, and Cleveland Bays) persisting throughout the study timeframe. This study suggested that intervention strategies, such as rehabilitation, should be able to be focussed on periods of heightened importance and specific localities to minimize health risks and contribute to sustainable use of resources. Jaylene Flint, Mark Flint, Colin J. Limpus, and Paul C. Mills Copyright © 2015 Jaylene Flint et al. All rights reserved. Polychaete Annelid Biomass Size Spectra: The Effects of Hypoxia Stress Tue, 27 Oct 2015 12:36:34 +0000 Quantitative benthic samples were taken during spring and summer at three locations on the Louisiana continental shelf from 2004 to 2012 to assess the influence of hypoxia on the mean sizes (wet weight) of polychaete annelid worms. While the mean body size over the entire study of 64 samples was 3.99 ± 4.66 mg wet weight per individual, the mean ranged from 2.97 ± 2.87 mg during consistently hypoxic conditions (<2 mg/L) to a high of 7.13 ± 7.60 mg () under oxic conditions (>2 mg/L). The variations in size within assemblages were estimated from conventional biomass size spectra (BSS) and normalized biomass size spectra (NBSS) across a broad range of oxygen concentrations. The decline in size was due to the elimination of large species under hypoxic conditions (<2 mg/L), not a reduction in size within species. At “severe” levels of hypoxia (<1 mg/L), the smallest species also declined in abundance, whereas the ubiquitous “medium-sized” Paraprionospio pinnata flourished. These results suggest that there will be enhanced selection for small sizes and species with enlarged branchial palps such as those in P. pinnata if, as predicted, hypoxia becomes more commonplace in time and space worldwide. Fangyuan Qu, Clifton Nunnally, and Gilbert T. Rowe Copyright © 2015 Fangyuan Qu et al. All rights reserved. Comparison between Otoliths and Length Based Ageing and Growth of African Armoured Searobin (Peristedion cataphractum L. 1758; Teleostei, Peristediidae) off the Southern Coasts of Sicily (Mediterranean Sea) Wed, 30 Sep 2015 11:13:10 +0000 The recovering of Peristedion cataphractum otoliths collected between 1991 and 1992 from specimens sampled off the southern coasts of Sicily has allowed a direct ageing and growth estimation to be compared with the length based method estimates produced in successive years. Overall, 855 left otoliths (sagittae) were recovered, measured, and read as a whole surface. The core and rings distances were also measured to perform back-calculation. The otolith length-body length relationships were allometric. Back-calculated lengths at age were in agreement with the lengths estimated with otolith readings. Present results showed a good congruency between otoliths and length based method. Teresa Bottari, Salvatore Gancitano, Paola Rinelli, and Sergio Ragonese Copyright © 2015 Teresa Bottari et al. All rights reserved. A Parasite of Marine Rotifers: A New Lineage of Dinokaryotic Dinoflagellates (Dinophyceae) Thu, 17 Sep 2015 05:58:47 +0000 Dinoflagellate infections have been reported for different protistan and animal hosts. We report, for the first time, the association between a dinoflagellate parasite and a rotifer host, tentatively Synchaeta sp. (Rotifera), collected from the port of Valencia, NW Mediterranean Sea. The rotifer contained a sporangium with 100–200 thecate dinospores that develop synchronically through palintomic sporogenesis. This undescribed dinoflagellate forms a new and divergent fast-evolved lineage that branches among the dinokaryotic dinoflagellates. Fernando Gómez and Alf Skovgaard Copyright © 2015 Fernando Gómez and Alf Skovgaard. All rights reserved. On the Interplay between Cannibalism and Harvest in Stage-Structured Population Models Wed, 17 Jun 2015 07:32:58 +0000 By use of a nonlinear stage-structured population model the role of cannibalism and the combined role of cannibalism and harvest have been explored. Regarding the model, we prove that in most parts of parameter space it is permanent. We also show that the transfer from stability to nonstationary dynamics always occurs when the unique stable equilibrium undergoes a supercritical Neimark-Sacker (Hopf) bifurcation. Moreover, the dynamic consequences of catch depend not only on which part of the population (immature or mature) is exposed to increased harvest pressure but also on which part of the immature population (newborns, older immature individuals) suffers from cannibalism. Indeed, if only newborns are exposed to cannibalism an enlargement of harvest pressure on the mature part of the population may act in a stabilizing fashion. On the other hand, whenever the whole immature population is exposed to cannibalism there are parts in parameter space where increased harvest on the mature population acts in a destabilizing fashion. Arild Wikan Copyright © 2015 Arild Wikan. All rights reserved. Viability of Sea Fan Populations Impacted by Disease: Recruitment versus Incidence Tue, 26 May 2015 11:14:54 +0000 Diseases are a threat to the viability of an increasing number of coral populations. In this study we analyze the effect of infection and recruitment rate on the viability and structure of sea fan (Gorgonia ventalina) populations using a size-based matrix model parameterized with data from field studies. The model predicts that the viability of sea fan populations is strongly influenced by disease incidence and recruitment. Under high recruitment rate, the disease incidence threshold for population viability is 0.12/yr. However, populations with no or low incidence may also go locally extinct given persistent low recruitment. The model also predicts an effect of recruitment on disease prevalence. Everything else being equal, sites with low recruitment will exhibit higher disease prevalence than ones with high recruitment, particularly in medium and large colonies. Elasticity analysis reveals that changes in colony survivorship are likely to have the strongest effect on population growth rate, particularly given low recruitment. We conclude that under current levels of incidence sea fan populations in the Caribbean are not at risk. However, future epizootics are likely to produce local extinctions particularly if coinciding spatially or temporally with low recruitment. Alberto M. Sabat and Carlos Toledo-Hernández Copyright © 2015 Alberto M. Sabat and Carlos Toledo-Hernández. All rights reserved. Ultrastructural Comparison of Processing of Protein and Pigment in the Ink Gland of Four Species of Sea Hares Sun, 24 May 2015 11:25:04 +0000 The ink glands of four sea hare species (Aplysia californica, A. parvula, A. juliana, and Dolabrifera dolabrifera) were compared to determine where ink protein is synthesized, how it is incorporated into protein storage vesicles, and the degree of variation in the structure of the ink gland. Ink protein was synthesized in RER cells and stored in amber and white vesicles. Lack of competent RER cells in the ink gland of D. dolabrifera was correlated with the absence of ink protein. Ink protein had similar characteristics in all three Aplysia species but, again, it was absent in D. dolabrifera. Its uptake involved pinocytosis by protein vesicle cell membranes. Granulate cells showed little variation in structure among the four species, the opposite was the case for RER cells. The conversion of the red algal pigment, phycoerythrin, to phycoerythrobilin (PEB) occurs in the digestive gland but the change of PEB to aplysioviolin (APV), the form of pigment released by the ink gland, occurs in the ink gland itself by both granulate cells and pigment vesicles. The literature describes five types of vesicles based upon color and contents in the ink gland of these four species. We report only three types of vesicle: colored (purple), protein (white and amber), and transparent (includes clear vesicles). Jeffrey S. Prince and Paul Micah Johnson Copyright © 2015 Jeffrey S. Prince and Paul Micah Johnson. All rights reserved. Comparison of Three Methods for Determining the Prey Preference of the Muricid Snail Reishia clavigera Sun, 10 May 2015 11:59:28 +0000 We propose an appropriate method for investigating the prey preferences of the muricid snail Reishia clavigera (Küster, 1860) with limited collection of live prey. We compared 3 methods for examining the prey preference. The first was a predation experiment, conducted with dead prey instead of live prey. The second was a prey choice test using a few preys. In this experiment, both live and dead prey were used. The last method was a stable isotope analysis of R. clavigera and its putative prey items. Using live prey, bivalves were the most preferred prey, but goose barnacle was the most preferred prey species in experiments using dead prey. The carbon and nitrogen stable isotope analysis supported the live prey experiment. Since R. clavigera prefer preying on live prey but will scavenge or cannibalize when no other food is available in natural habitats, experimental methods using dead prey are not suitable for investigating its prey preferences. Considering the damage to natural habitats, the prey choice test is ecologically benign. Taken together, our findings suggested the prey choice test is the most appropriate method of identifying the prey preferences of muricid snails when large numbers of live preys are difficult to collect. Morihiko Tomatsuri and Koetsu Kon Copyright © 2015 Morihiko Tomatsuri and Koetsu Kon. All rights reserved. Origins and Implications of a Primary Crown-of-Thorns Starfish Outbreak in the Southern Great Barrier Reef Thu, 26 Mar 2015 12:04:15 +0000 The crown-of-thorns starfish (COTS) is a major predator of hard corals. Repeated COTS outbreaks in the Cairns and Central sections of the Great Barrier Reef (GBR) have been responsible for greater declines in coral cover than any other type of disturbance, including cyclones, disease, and coral bleaching. Knowledge of the precise timing and location of primary outbreaks could reveal the initial drivers of outbreaks and so could indicate possible management measures. In the central GBR, COTS outbreaks appear to follow major flooding events, but despite many years of observations, no primary outbreak has ever been unequivocally identified in the central and northern GBR. Here we locate a primary outbreak of COTS on the southern GBR which is not correlated with flooding. Instead it appears to have been the result of a combination of life history traits of COTS and prevailing oceanographic conditions. The hydrodynamic setting implies that the outbreak could disperse larvae to other reefs in the region. Ian Miller, Hugh Sweatman, Alistair Cheal, Mike Emslie, Kerryn Johns, Michelle Jonker, and Kate Osborne Copyright © 2015 Ian Miller et al. All rights reserved. Seasonal Changes in Glycogen Contents in Various Tissues of the Edible Bivalves, Pen Shell Atrina lischkeana, Ark Shell Scapharca kagoshimensis, and Manila Clam Ruditapes philippinarum in West Japan Tue, 24 Feb 2015 06:38:07 +0000 The types of tissues accumulating glycogen and seasonal changes in glycogen content were investigated in the following shell species: pen shell Atrina lischkeana, ark shell Scapharca kagoshimensis, and Manila clam Ruditapes philippinarum. Comparison of the results showed that the adductor muscle or foot was the main glycogen reservoir and the levels varied seasonally. The adductor muscle in the pen shell showed higher glycogen content during spring and lower content during autumn. The ark shell, on the other hand, showed higher content during winter and spring and lower content during summer and autumn, while the Manila clam showed higher glycogen content during spring and summer and lower content during autumn and winter. These results revealed that the adductor muscle in pen shells and the foot in ark shells and Manila clams act as the main storage tissues for glycogen in the three species studied and that these tissues are suitable to analyze glycogen prevalence to estimate individual physiological condition. Tatsuya Yurimoto Copyright © 2015 Tatsuya Yurimoto. All rights reserved. Estimating the Potential Production of the Brown Mussel Perna perna (Linnaeus, 1758) Reared in Three Tropical Bays by Different Methods of Condition Indices Thu, 22 Jan 2015 09:31:09 +0000 Perna perna (Linnaeus, 1758) is the main marine bivalve mussel yielded commercially in Brazil. In spite of this, scientific data is very scarce regarding its productivity in tropical shallow waters. The Condition Index (CI) is used worldwide in mariculture to assess animal health, harvest time, and yield. In this study, the authors used CI results from nine different methods to assess the season effect on the mussel CI and also to evaluate the potential yield of three southern Brazilian bays. The results from nine CI methods were used for the comparison of the seasonality and yield of mussels reared in three marine bays. Sampling was carried out monthly within two 4-month periods, from December 2008 to August 2009. The results show a trend for seasonal effects on the CI results. The winter months showed the highest and the lowest values. Between bays, higher CI values were detected in animals reared at Sepetiba Bay, followed by Guanabara Bay and Ilha Grande Bay. We suggest that the CI (that considers the ratio between bivalve soft tissue wet weight and total length) should be used by fishermen, since this formula was able to detect differences between sites and is more easily applied. Petrus Galvao, Renan Longo, João Paulo Machado Torres, and Olaf Malm Copyright © 2015 Petrus Galvao et al. All rights reserved. Composition of Periphyton Community on Water Hyacinth (Eichhornia crassipes): In Analysis of Environmental Characteristics at Ejirin Part of Epe Lagoon in Southwestern Nigeria Thu, 08 Jan 2015 08:34:57 +0000 The composition of periphyton community on water hyacinth was investigated at Ejirin, part of Epe Lagoon, in relation to environmental characteristics from December 2012 to May 2013. A total of 14,536 individuals of 104 species belonging to five divisions were identified, with Bacillariophyta (82.69%), Cyanobacteria (10.43%), Chlorophyta (5.63%), and Euglenophyta (1.15%). The total species abundance observed showed a strong correlation with rainfall () and strongly significant correlation with TDS (; ). Biochemical oxygen demand value remained (BOD) 4.8 mg/L while Shannon-Wiener index value remained (. The presence of the following organisms could be used as an indicator of environmentally stressed aquatic ecosystem: euglenoids, blue green algae, Nitzschia palea, Surirella sp., Pinnularia sp., Gomphonema parvulum, Mougeotia sp., Spirogyra sp., Trachelomonas affinis (Lemm.), and T. ensifera Daday; T. gibberosa Playf. and Phormidium articulatum; Lyngbya intermedia; Cymbella ventricosa; Eunotia arcus; Surirella linearis and Closterium parvulum Nag. A. I. Inyang, K. E. Sunday, and D. I. Nwankwo Copyright © 2015 A. I. Inyang et al. All rights reserved. Catalase Activity in Brown Mussels (Perna perna) under Acute Cadmium, Lead, and Copper Exposure and Depuration Tests Thu, 25 Dec 2014 09:32:31 +0000 Brown mussels (Perna perna) were exposed to cadmium (Cd), lead (Pb), and copper (Cu) concentrations under acute exposure and exposure-depuration tests for the estimation of biochemical biomarker catalase (CAT). The acute tests showed accumulated Cd, Pb, and Cu in Perna perna correlated linearly with the exposure concentrations (, , and for Cd, Pb, and Cu, resp.). The results of CAT increased significantly in tissues of treatment mussels after 72 h exposure when compared to control. The values of total protein were disturbed in exposed groups when compared with control. These results suggest that metabolites and catalase activity were affected by heavy metal exposures. Analysis using the Spearman rank correlation coefficient showed that the CAT activity appeared to have a significant positive correlativity (, , and for Cd, Pb, and Cu, resp.) with the accumulated Cd, Pb, and Cu concentrations, respectively. The result of exposure-depuration tests showed that there is a general tendency for CAT to decrease in depuration phase, suggesting that the induction of catalase is metal and/or mixture of metals dependent. Kamel Boudjema, Sidali Kourdali, Nabila Bounakous, Abdellah Meknachi, and Abdelmalek Badis Copyright © 2014 Kamel Boudjema et al. All rights reserved. Olive Ridley Sea Turtle Hatching Success as a Function of Microbial Abundance and the Microenvironment of In Situ Nest Sand at Ostional, Costa Rica Mon, 22 Dec 2014 00:10:05 +0000 Sea turtle hatching success at mass nesting beaches is typically lower than at solitary nesting beaches, presumably due in part to high rates of microbial metabolism resulting from the large input of organic matter from turtle eggs. Therefore, we tested the hypothesis that hatching success varies across areas of the beach in conjunction with differences in the physical nest environment and microbial abundance of in situ olive ridley sea turtle nests at Ostional, Costa Rica. We marked natural nests in high-density, low-density, and tidal-wash nesting areas of the beach and monitored clutch pO2 and temperature throughout the incubation period. We quantified hatching success and collected samples of nest sand during nest excavations. We quantified microbial abundance (bacteria and fungi) with a quantitative polymerase chain reaction (qPCR) analysis. Hatching success was lower in nests with lower pO2, higher temperatures, higher organic matter content, and higher microbial abundance. Our results suggest that the lower oxygen within the nest environment is likely a result of the high microbial abundance and rates of decomposition in the nest sand and that these factors, along with increased temperature of clutches in the high-density nesting area, are collectively responsible for the low hatching success at Ostional. Vanessa S. Bézy, Roldán A. Valverde, and Craig J. Plante Copyright © 2014 Vanessa S. Bézy et al. All rights reserved. The First Molecular Characterization of Picocyanobacteria from the Argentine Sea Thu, 20 Nov 2014 00:00:00 +0000 Picocyanobacteria are abundant throughout the world’s oceans. Particularly, it has been reported that Synechococcus strains have a wide latitudinal distribution, from polar to tropical waters. However, their molecular characterization in the Southwest Atlantic Ocean is still missing. We analyzed Synechococcus genetic diversity in a sector of the Argentine Sea, one of the richest biological areas of the world oceans. 16S rRNA amplicons obtained after PCR amplification of environmental DNA extracted from water samples of this area were used for DGGE and sequenced. Only Synechococcus sequences could be retrieved. On the other hand, we isolated two Synechococcus strains from the environment. Our analyses revealed that the clade I group was widespread from latitude 38°S to 48°S and that can coexist with clade IV strains in shelf waters. The cooccurrence of these two clades may be related to an adaptation to high-nutrient/low-temperature waters. Our data are the first report on Synechococcus ecotypes that would be important contributors to phytoplankton biomass in the Argentine Sea, one of the richest biological areas of the world oceans. Macarena Perez-Cenci, Gonzalo F. Caló, Ricardo I. Silva, Rubén M. Negri, and Graciela L. Salerno Copyright © 2014 Macarena Perez-Cenci et al. All rights reserved. Abundance and Diversity of Holothuroids in Shallow Habitats of the Northern Red Sea Thu, 13 Nov 2014 08:33:44 +0000 Holothuroid sea cucumbers are vital members of Coral Reefs and associated marine habitats and provide vital ecological services. In the southern regions of the Red Sea their populations have been decimated by overfishing. The main objective of this study was to test the hypothesis that the northern part of the Red Sea serves as an ecological refuge for the species threatened farther to the south. Accordingly, populations of sea cucumbers in 4 shallow sites south of Eilat, Israel (29°33′00N 34°57′14E), were repeatedly surveyed from November 2013 to April 2014. Overall 11 species were observed in these shallow sites. Their abundance and diversity differed significantly between sites, but not temporally. In sites in marine protected areas, with an intact fringing reef, diversity was high, with Holothuria edulis and Bohadschia sp. being the most common species. In areas with higher human use and characterized by rubble and scattered corals, diversity was low, and Actinopyga bannwarthi was the most common species. The observed abundance and diversity did not support the refuge hypothesis. These findings are discussed in relation to other surveys of abundance and diversity in similar habitats. Boaz Yuval, Lee Sudai, and Yarden Ziv Copyright © 2014 Boaz Yuval et al. All rights reserved. Cetacean Presence in the Trincomalee Bay and Adjacent Waters, Sri Lanka Tue, 21 Oct 2014 07:30:52 +0000 In Sri Lanka thirty species of cetaceans have been recorded to date. The canyon at Trincomalee bay is a multiple submarine canyon complex and anecdotal reports suggest that the Trincomalee bay and its adjacent waters are utilised by a number of cetacean species. Though Cetaceans are known to be abundant in the waters off Trincomalee there is a dearth of research and data pertaining to the abundance and species frequenting the Trincomalee bay and its adjacent waters. As such the current study was initiated, to get a consensus of the abundance and occurrences of species in Trincomalee Bay and its adjacent waters. Field surveys were carried out for 19 months and the research platform was a 35-foot commercial fishing vessel. 177 cetacean encounters were recorded on 67 of the 75 field days. Remarkably a total of 11 species of cetaceans which composed of two species of Baleen Whales and nine species of Toothed Whales were recorded. Delphinidae was the most common family recorded, followed by Balaenopteridae, Ziphiidae, Physeteridae, and Kogiidae. Spinner Dolphins were the most abundant cetacean owing to the large pods observed and the regularity of the sightings. They were the only species seen feeding/traveling with birds and fish (tuna). Sperm Whales, Blue Whales, and Bryde’s Whales were also relatively common. Two records of interspecific association between cetaceans were recorded. The increase in the human population in the study area has resulted in the overexploitation of marine resources which has dire repercussions on the marine mammal communities found in these waters. Ranil P. Nanayakkara, Jayampathi Herath, and Ruvinda K. de Mel Copyright © 2014 Ranil P. Nanayakkara et al. All rights reserved. Development of Enzymes and In Vitro Digestibility during Metamorphosis and Molting of Blue Swimming Crab (Portunus pelagicus) Wed, 08 Oct 2014 09:24:15 +0000 The work focuses on development of digestive enzymes (amylase, total protease, trypsin, and chymotrypsin) and activity ratio of trypsin to chymotrypsin (T/C ratio) for digestive efficiency and growth, in blue swimming crab (Portunus pelagicus) during metamorphosis and molting. Specific activities of all enzyme parameters studied were associated with growth during metamorphosis, while only those of trypsin and T/C ratio were associated during molting cycle where trypsin and chymotrypsin specific activities associated with consumption rate with especially high levels during late intermolt and early premolt stages. About 50% increased weight gain was observed with at least double increased T/C ratio at the end of molting period, compared to the stages prior to molting. Growth of carapace would be more significant after finishing molting. Carapace width gain and T/C ratio were highest at the first crab stage. Studies of in vitro protein digestibility of different feed raw materials indicated that Artemia, Rotifer, and Moina are the best for larval stages. Otherwise, the use of shrimp feed and Artemia flake could be the alternatives. Incorporating of cassava meal into the feed formula for early adult stage (juvenile) could be an advantage. The proteins from animals are more beneficial for adult crab culture than the proteins from plants and bacteria. The digestible quality of dietary protein is very important during larval stages, while the protein level of diet is more important during adult stages with fully developed digestive enzymes. Phanu Chamchuen, Boonyarath Pratoomchat, Arunee Engkakul, Uthaiwan Kovitvadhi, and Krisna Rungruangsak-Torrissen Copyright © 2014 Phanu Chamchuen et al. All rights reserved. Harvesting Model for Fishery Resource with Reserve Area and Bird Predator Mon, 22 Sep 2014 09:14:01 +0000 The aim of this paper is to study the dynamics of fishery resource with reserve area in the presence of bird predator. The aquatic region under investigation is divided into two zones: one free for fishing and another restricted for any kind of fishery. The criteria of biological and bionomic equilibrium of system are established. The points of local stability, global stability, and instability are obtained for the proposed model. An optimal harvesting policy is established using Pontryagin’s maximum principle. At last the theoretical results obtained are illustrated with the help of numerical simulation. Amit Sharma and Bhanu Gupta Copyright © 2014 Amit Sharma and Bhanu Gupta. All rights reserved. Locomotion and Functional Spine Morphology of the Heart Urchin Brisaster fragilis, with Comparisons to B. latifrons Mon, 22 Sep 2014 06:57:54 +0000 The heart urchin Brisaster fragilis is an important bioturbator found in the Estuary and Gulf of St. Lawrence. Several adaptations allow it to move within fine sediments (e.g., test shape, spine morphology, and distribution), which are compared here to those of its Pacific sibling species B. latifrons. While ventral spatulate spines and dorsal and anterolateral curvilinear spines are similar between the two species, anterior spines differ significantly: sigmoid-shaped for B. fragilis and curvilinear for B. latifrons. This morphological difference, in addition to a narrower plastron for B. fragilis, suggests a different digging strategy. In situ video observations of B. fragilis show a “dig and move” strategy: anterior spines “dig” forward at the sediment while the plastron spines “move” the urchin into the newly created space. B. latifrons on the other hand uses an oblique rocking motion. This suggests that generalizations derived from one or few species displaying similar body shapes may not be possible. Factors such as sediment depth (i.e., the amount of sediment above the urchin) are likely to affect movement and force the animal to employ a different digging strategy, even within a single species. The role of spines for locomotion is further discussed, with additional reference to tubercle morphology. Danielle E. Walker and Jean-Marc Gagnon Copyright © 2014 Danielle E. Walker and Jean-Marc Gagnon. All rights reserved. Dynamic Changes in Bacterial Population and Corresponding Exoenzyme Activity in Response to a Tropical Phytoplankton Bloom Chattonella marina Sun, 21 Sep 2014 08:31:18 +0000 The raphidophyte Chattonella marina (Subrahmanyan) Hara & Chihara bloom which causes lethal effects on marine ecosystem has been reported intermittently from Indian waters. In the present study, periodic samplings were made in a Chattonella marina bloom area, off Mahe, on 27 and 29 October and 1 November 2011 (in different phases of the bloom) to assess the associated bacterial population and their exoenzyme activity. Microbial community composition of Chattonella marina bloom revealed a twentyfold increase in bacterial load over the nonbloom area. The bacterial genera, Micrococcus, Flavobacterium, Vibrio, and Pseudomonas, increased significantly during the declining phase of the bloom. An assessment of the extracellular enzyme production also showed a marked increase in percentage of bacterial strains, potent in protease production, suggesting the possible role of proteolytic bacteria in bloom crash. This study reveals the bacterial community succession during the bloom and indicates that bacteria play an important role in bloom regulation. Anit M. Thomas, M. G. Sanilkumar, K. C. Vijayalakshmi, A. A. Mohamed Hatha, and A. V. Saramma Copyright © 2014 Anit M. Thomas et al. All rights reserved. Gametogenesis, Embryogenesis, and Fertilization Ecology of Platygyra acuta in Marginal Nonreefal Coral Communities in Hong Kong Mon, 08 Sep 2014 09:00:49 +0000 Understanding the reproductive biology of dominant coral species in subtropical nonreefal coral communities is critical in providing important information on the processes underlying the distribution limits of coral species and communities. This is the first study that investigates the reproduction cycle, gametogenesis, and fertilization ecology of Platygyra acuta. Results indicated that P. acuta is hermaphroditic and exhibits a single annual gametogenic cycle. Oogenic and spermatogenic cycle occurs for 6-7 months and for 2 months, respectively, prior to annual mass spawning event in May to June in Hong Kong. It took 18 hours for P. acuta to complete embryonic development, develop cilia, and start to rotate. High (>70%) fertilization success can be achieved under a broad range of sperm concentrations from 104 to 107 sperms mL−1. Fertilization success remained consistently high 6 h after spawning, indicating a prolonged viability of its gametes that is much longer than that recorded for other coral species. Significantly higher percentage of fertilization success was recorded in the first of the two consecutive nights of spawning, suggesting differences in the quality of the eggs and/or sperms between days of spawning. These results serve as important baseline information for better understanding of corals in marginal communities. Apple Pui Yi Chui, Man Chung Wong, Siu Hong Liu, Ga Wun Lee, Sze Wai Chan, Pui Ling Lau, Sin Man Leung, and Put Ang Jr. Copyright © 2014 Apple Pui Yi Chui et al. All rights reserved. Ecological Significance of the Association between Stomopneustes variolaris (Echinoidea) and Lumbrineris latreilli (Polychaeta) from Visakhapatnam Coast, India Thu, 14 Aug 2014 07:29:17 +0000 The present study reports a new association between the sea urchin Stomopneustes variolaris (Lamarck, 1816) and the polychaete Lumbrineris latreilli (Audouin & Milne Edwards, 1834) based on the specimens collected intertidally at Bay of Bengal (Visakhapatnam, east coast of India). Out of 60 sea urchins collected, 10 (16.67%) were associated with the polychaete. The prevalence increased with the increasing sea urchin test diameter. All polychaetes were exclusively found between the spines, in the aboral region of the host. This association protects the polychaete from the predators during displacement from its natural habitat. Archana Ayyagari and Ramesh Babu Kondamudi Copyright © 2014 Archana Ayyagari and Ramesh Babu Kondamudi. All rights reserved. Variability in the Structure of Phytoplankton Assemblages in relation to Human Disturbance in Southern Coast of Tunisia Wed, 25 Jun 2014 00:00:00 +0000 We investigated the impact of industrial effluents on phytoplankton assemblage in southern Tunisia (Skhira). We specifically addressed changes in microalgae composition caused by this anthropogenic interference. A hierarchical sampling design was used to compare planktonic microalgae structure between one disturbed station and one control station. Samples were collected by scuba diving at 5 m depth in August 2012. A total of 76 microalgae taxa were identified. Dinoflagellates abundance was low in the disturbed station, especially Gonyaulacales and Prorocentrales due to P-limitation, whereas diatoms and cyanobacteria abundance were low in control station which is characterized by Si-limitation. Lotfi Mabrouk, Lamia Dammak, Asma Hamza, Mabrouka Mahfoudhi, and Med-Najmeddine Bradai Copyright © 2014 Lotfi Mabrouk et al. All rights reserved. A Comparison of Abundance and Diversity of Epiphytic Microalgal Assemblages on the Leaves of the Seagrasses Posidonia oceanica (L.) and Cymodocea nodosa (Ucria) Asch in Eastern Tunisia Tue, 03 Jun 2014 00:00:00 +0000 We studied spatial patterns in assemblages of epiphytic microalgae on the leaves of two seagrass species with different morphologies and longevity, Cymodocea nodosa and Posidonia oceanica, which cooccur in Chebba in Eastern Tunisia. Epiphyte assemblages were described for each species in summer. Epiphyte microalgal assemblages were more abundant on the leaves of C. nodosa but more diversified on the leaves of P. oceanica. We suggest that the differences in species composition and abundance between those seagrass species may reflect an interaction of timescales of seagrass longevity with timescales of algal reproductive biology. Short-lived C. nodosa was dominated by fast growing species such as the cyanobacteria species Oscillatoria sp., while P. oceanica leaves were colonized by more mature and diversified species such as Prorocentrales. Local environmental conditions (hydrodynamics, light penetration), host characteristics (meadow type, shapes forms of leaves, life span, and growth rate), and grazing effect seem also to be responsible for these dissimilarities in epiphytic microalgae communities. Lotfi Mabrouk, Mounir Ben Brahim, Asma Hamza, Mabrouka Mahfoudhi, and Med Najmeddine Bradai Copyright © 2014 Lotfi Mabrouk et al. All rights reserved.