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Protected areas not allowing extractive activities (here called fully protected area) are a spatially explicit conservation management tool commonly used to ensure populations persistence. This is achieved when an adequate fraction of a species' population spends most of its time within the boundaries of the protected area. Within a marine context, home ranges represent a tractable metric to provide guidance and evaluation of fully protected areas. We compiled peer-reviewed literature specific to the home ranges of finfishes and invertebrates of ecological and/or commercial importance in the Mediterranean Sea, and related this to the size of 184 Mediterranean fully protected areas. We also investigated the influence of fully protected areas size on fish density in contrast to fished areas with respect to home ranges. Home range estimations were available for 11 species (10 fishes and 1 lobster). The European spiny lobster Palinurus elephas had the smallest home range (0.0039 ± 0.0014 km 2 ; mean ± 1 SE), while the painted comber Serranus scriba (1.1075 ± 0.2040 km 2 ) had the largest. Approximately 25% of Mediterranean fully protected areas are larger than 2 times the size of the largest home range recorded. Fish densities were significantly higher when fully protected areas were larger than the home range, while no change in density occurred when home ranges were larger than fully protected areas. These results display a direct link between the effectiveness of fully protected areas and species' home range, suggesting that fully protected areas of at least 3.6 km 2 may increase the density of local populations of these coastal marine species. [ABSTRACT FROM AUTHOR]

Recently, fisheries managers have been faced with high uncertainty about Atlantic goliath grouper ( Epinephelus itajara ) stock status, especially due to the lack of fishery-dependent data since the harvest moratorium in 1990. Regardless of this uncertainty, the angling community has been pressuring fishery managers to open the goliath grouper to recreational take, while the diving community has been pressuring managers to keep the fishery closed due to the touted ecotourism value of the spawning aggregations. A previous study estimated that resident anglers in Florida who wanted the fishery open were willing to pay between US$34 and US$79 to harvest a goliath grouper. Using a survey instrument with choice experiments, the present study estimated that divers ( n = 1537) off eastern Florida would be willing to pay approximately US$103 for a dive trip with one goliath grouper encounter during the months of their spawning aggregation (August–October), and US$202 if there are 40 goliath grouper (such as is common on a many spawning aggregation sites). Results suggested that divers coming from outside of Florida were willing to pay higher rates for dive trips with goliath grouper encounters; and at spawning aggregations sites, willingness to pay was estimated around US$336 for these non-Florida divers. Based on life-history traits of goliath grouper and the high value of their spawning aggregation sites, we suggest any changes in goliath grouper policy that would negatively impact spawning aggregation numbers be made with caution. [ABSTRACT FROM AUTHOR]

Parental contributions of giant grouper to communal spawns in captivity are important for establishing genetic management of the species. In this study, we have followed the spawning dynamics of three males and three females over six to eight consecutive days, over three time periods. Polymorphic microsatellite markers were validated and utilised to successfully determine parentage in 574 offspring from 20 nights of spawns. Variation of both maternal and paternal contributions between nights in batches of spawns was significant (P < 0.001). Most paternal assignments were attributed to one dominant male who initiated each spawning batch, however, all males and females successfully mated over the spawning period. There was a significant (P < 0.01) trend towards a polygamous reproductive mode for giant grouper: in two of the three batches of spawns, where on some nights, eggs from all females were fertilised by multiple males. Genetic variation was assessed between parents and offspring. There was a loss of alleles on each spawning night, however, if offspring from a series of consecutive nights were combined, most or all of the genetic variation would be maintained in the F 1 generation. This research validates the use of molecular tools for genetic monitoring of giant grouper and improves the understanding of spawning dynamics of protogynous hermaphroditic communal spawners over time in an aquaculture setting. Statement of relevance The finding of this study shows that the dominant giant grouper male initiates spawning and is the primary contributor however other males contribute to spawns. This contributes to our understanding of grouper spawning behaviour, and offers important information to grouper growers with respect to the need to collect eggs over consecutive days to ensure that the full genetic diversity is captured. [ABSTRACT FROM AUTHOR]

The present study established and confirmed an efficient technology for groupers: giant grouper Epinephelus lanceolatus , orange-spotted grouper E. coioides , seven-band grouper, E. septemfasciatus , and kelp grouper E. moara sperm cryopreservation and successfully applied the cryopreserved E. lanceolatus sperm into interspecific hybridization with E. coioides . For both E. lanceolatus and E. coioides, the best motility of postthaw sperm were achieved using 6% to 10% DMSO, 6% to 16% propylene glycol, and 6% ethylene glycol as cryoprotectants. Furthermore, we have successfully applied this method into the other two species of E. septemfasciatus (74.56 ± 5.45%) and E. moara (71.67 ± 5.10%) sperm cryopreservation and obtained high motility, respectively. Computer-assisted sperm motion analysis showed that the postthaw sperm of the four species of grouper could keep 30 to 35 minutes motile state in nature seawater. And the freezing–thawing process decreased the sperm motility, speed, and longevity but did not significantly change the sperm movement pattern, and the progressive linear motion still was the dominant movement pattern. For the four species of grouper, the ultrastructural analysis showed 70% to 80% of the spermatozoa had intact morphology with a little of swelling; 20% to 30% were damaged, such as swelling or rupture of head, midpiece, and tail region; and 10% to 20% were severely damaged. Whereas, by the microscopic observation, more than 90% of the postthaw sperm presented normal morphology. In the artificial insemination and hybridization experiment, high fertilization rates and hatching rates were achieved when using 10% DMSO (88.7 ± 5.3%, 85.3 ± 7.4%) and 10% propylene glycol (86.8 ± 3.3%, 83.1 ± 6.6%), with no significant difference in comparison with control (92.2 ± 1.4%, 87.9 ± 4.2%). In addition, we found the embryos from postthaw sperm of E. lanceolatus and E. coioides eggs developed and grew normally as reported in previous study on hybridization of groupers ( E. coioides × E. lanceolatus ) using cryopreserved sperm. The results of the present study further validated the safety of the cryopreserved sperm in breeding production by assessing the fertilization capacity, embryo development, and larval growth. [ABSTRACT FROM AUTHOR]

Sparing marine-origin protein and lipid was investigated in diets for giant grouper ( Epinephelus lanceolatus ), using various combinations of soybean meal (SBM), soy protein concentrate (SPC), and an algal meal derived from Schizochytrium limacinum (ALG) to replace fish meal (FM), squid meal (SQM) and fish oil (FO). Diets were formulated to contain 45% protein (dry weight) and 10% lipid. Three diets were derived from this formulation, using combinations of SBM, SPC, and ALG to replace 20% (FM80), 40% (FM60), or 80% (FM20) of the marine-origin protein sources; additionally, incorporation of the lipid-dense ALG resulted in complete FO replacement in the FM60 and FM20 diets. A feeding experiment was carried out in a seawater recirculating system with 12, 90-L tanks initially stocked with 6 fish each (individual weight = 45.9 ± 7.1 g) and maintained at 25 °C. Diets were assigned to tanks in triplicate, fish were fed to apparent satiation twice daily for 12 weeks, and growth rate, body composition, nutrient retention, survival, hepatosomatic index and intestinal integrity were subsequently evaluated. With the exception of retained lipid, the FM100, FM80, and FM60 diets all yielded equivalent (P > 0.05) growth and feed utilization. In comparison, weight gain, specific growth rate, feed intake, retained nitrogen and retained lipid were significantly reduced in fish fed the FM20 feed, whereas FCR was significantly elevated. Amino acid analysis of the diets indicated that methionine was limiting in the FM20 feed. Hepatosomatic index did not vary among treatments, but other aspects of body composition were affected. Carcass lipid and ash significantly decreased with marine ingredient inclusion; carcass protein also varied, though less appreciably and without a clear pattern. Fillet fatty acid profile reflected dietary composition. The FM100 diet yielded the highest fillet EPA content, whereas DHA content, DHA:EPA and n − 3:n − 6 ratios, and total long-chain polyunsaturated fatty acids increased with dietary inclusion of ALG. Histological analysis revealed progressive morphological changes to the distal intestine with higher levels of FM replacement, suggesting enteritis among fish fed the FM20 feed. It is concluded that a blend of SBM, SPC, and ALG can replace at least 40% of marine protein sources, and ALG can be used as the main lipid source in diets for E. lanceolatus without significantly affecting fish performance or condition. Statement of relevance The results of this work contribute to decrease the dependence on protein and lipids from reduction fisheries traditionally used in commercial feeds for carnivorous fish, potentially improving the sustainability of aquaculture production of marine fish. [ABSTRACT FROM AUTHOR]

A ranavirus was isolated from the diseased farmed groupers (Grouper iridovirus in genus Ranavirus, GIV-R), Epinephelus hybrids (blotchy rock cod, Epinephelus fuscoguttatus ♀ × giant grouper, Epinephelus lanceolatus ♂), in Sanya, Hainan, in July 2013. In this study, susceptibility of farmed juvenile giant grouper E. lanceolatus to GIV-R was determined by intraperitoneally injection. The cumulative mortality reached to 81% at 5 day post infection. Histologically, severe degeneration with massive pycnotic nuclei in spleen and kidney tissues was observed, and some small-size inclusion body-bearing cells (IBCs) existed in spleen. Hemorrhage and infiltration of inflammatory cells were presented in gill, liver and heart along with tissue degeneration and necrosis of varying severity. The results of immunohistochemistry analysis showed that the strongest immunolabellings were obtained from the kidney and spleen tissues, while intermediate intensity signals were observed in the heart, stomach, gill and liver tissues, and the weakest signals were obtained from the intestine and brain, but no signal was obtained in eyes. Electron microscopy revealed that spleen of moribund fish contained many viral particles in cytoplasm. Interestingly, in surviving fish, abnormal hypertrophic cells were observed in both splenic corpuscle and renal corpuscle, while no hypertrophic cell was observed in the other parts of spleen and kidney tissues. Moreover, immunolabellings only stained the hypertrophic cells in splenic corpuscle and renal corpuscle. This indicated that splenic corpuscle and renal corpuscle play an important role in GIV-R infection and replication. [ABSTRACT FROM AUTHOR]

Despite uncertainties surrounding the protected Atlantic goliath grouper's stock size and resilience, fishery managers are under pressure to end the harvest moratorium in place since 1990. The present study sought to measure the proportion of anglers interested in reopening the goliath grouper fishery and to identify key reasons for this interest. We also present an estimate of the amount that anglers would be willing to pay for a goliath grouper harvest tag (the right sold to an angler to harvest one goliath grouper). A survey was mailed to a random sample of Florida (USA) residents with a recreational fishing license. Approximately half of the respondents agreed that the goliath grouper should now be open to recreational take. A probit analysis indicated that the best predictor for the opinion the fishery should be open is the belief that there are “too many goliath grouper.” Also, more anglers agreed than disagreed that goliath grouper are eating “all the fish on the reef,” a belief that was related to anglers personally viewing goliath grouper depredation. The mean willingness to pay for a goliath grouper harvest tag was estimated to be between $34 and $79. This information can be used to estimate the potential revenues available from a hypothetical tag system and can be compared with the economic value of goliath grouper in non-consumptive uses such as recreational diving. [ABSTRACT FROM AUTHOR]

Epinephelus itajara is one of the marine fish species most threatened for extinction and it is considered to be “critically endangered” by the IUCN. The present study evaluated the genetic diversity of the species and the genetic/evolutionary relationships of its populations along the Atlantic coast of South America. The results indicate relatively reduced genetic variation, re-emphasizing the low adaptive potential of the species. One of the populations presented relatively high degrees of genetic diversity and it is evolutionary isolated from the all other populations. The evidences indicate the existence of two Evolutionarily Significant Units comprising E. itajara in the Atlantic coast of South America and the conservation prospects for the species must take these evidences into account. [ABSTRACT FROM AUTHOR]

Abstract: This study examined the effect of three extenders, Marine Fish Ringer (MFR), sodium citrate (CT), and sodium chloride (NaCl) and two cryoprotectants (10% dimethyl sulfoxide—DMSO and 15% Trehalose) on the cryopreservation of giant grouper, Epinephelus lanceolatus sperm which was later used for hybridization trial with orange-spotted grouper, Epinephelus coioides. Fish Ringer and sodium citrate as extenders resulted in higher fertilization (71±3 and 68±4%, respectively) than NaCl (58±1%). There was no difference in percent fertilization and hatch between DMSO and Trehalose and all combinations of extenders and cryoprotectants tested. Successful hybridization of E. coioides x E. lanceolatus was achieved for the first time between these two species using cryopreserved sperm from giant grouper. There was no difference in percent fertilization and hatch between hybrid and nonhybrid, orange-spotted grouper, but percent deformity of the hybrids (47%) was higher (P <0.05) than non-hybrid (21%). Survival (22%) of the hybrid was lower than non-hybrid (51%) 12days post hatching (first feeding period). However, this difference was not significant at the end of 45-day study period. Development stages were also not different between hybrids and non-hybrids during the observation period, except hybrid grouper exhibited yellow color with 5–7 oblique black bars across their lateral lines, similar to that of giant grouper by day 45 post hatching. This study successfully demonstrated the use of cryopreserved sperm from giant grouper to produce E. coioides x E. lanceolatus hybrid offsprings thus, laying the groundwork for further comparative studies on hybrid performance. [Copyright &y& Elsevier]

Sustainable marine aquaculture requires the definition of adequate areas for its development, where the productive activity has a lower impact on the environment and avoid conflicts with other coastal activities. The aim of this research is to identify the potential areas for marine aquaculture operations in the central and northern Pacific coast of Costa Rica, considering five fish species of commercial interest and three operation scale scenarios (large, medium and small scale). The mapping procedure considers the biological suitability for the species to have an optimum development, the structural suitability for the fish cages to endure the environmental conditions (mainly waves and currents), and the operational suitability for operation and maintenance activities associated to the fish production (e.g. feeding, harvesting, maintenance). Sea surface temperature, salinity, water clarity, wind speed and currents in open coasts regions were obtained from global models and satellite data. Currents and wave data in the Gulf of Nicoya, one of the main estuaries of the country, were modeled numerically. Available docking sites, marine protected areas and tourism sites were used and obtained from the corresponding national official entities. Results show a high potential for marine aquaculture projects, specifically for large and medium scale operations. Three out of five study species present high suitability in most of the study site, and the other two species present promising results in the Gulf of Nicoya. Small scale operations have several areas with high suitability for marine aquaculture projects, with extensions ranging from 101 km2 to 2 118 km2 depending on the species. At a regional scale, the Pacific coast of Costa Rica presents high potential for fish aquaculture, being a promising development medium for coastal communities as long as it is environmentally sustainable and compatible with other coastal activities such as tourism. [Display omitted] [ABSTRACT FROM AUTHOR]