Occurrence of <i>Philometra lateolabracis</i> (Nematoda: Philometridae) in the gonads of marine perciform fishes in the Mediterranean region

Gravid females of the nematode Philometra lateolabracis (Yamaguti, 1935), a parasite of gonads of marine perciform fishes, were found in wild and cultured dusky grouper Epinephelus marginatus (Lowe) from waters near the Balear Islands (Spain, Mediterranean Sea) and Sicily (Italy, Thyrrenean Sea), and in the greater amberjack Seriola dumerili (Risso) in Croatia (south-eastern Adriatic Sea). In wild E. marginatus in Spain, the overall prevalence was 21% and the intensity of infection 1 nematode per fish. The nematodes are briefly described and illustrated. The species Sanguinofilaria jordanoi López-Neyra, 1951, described from the ovary of Epinephelus gigas Brünich from Morocco, is synonymized with P. lateolabracis. This is the first documented record of P. lateolabracis from fishes of the Mediterranean region and its finding in S. dumerili represents a new host record. The possible importance of this pathogenic parasite for cultures of marine perciform fishes in the region is stressed

Distribution, age, and growth of young-of-the year greater amberjack (Seriola dumerili) associated with pelagic Sargassum

Patterns of distribution and growth were examined for young-of-the-year (YOY) greater amberjack (Seriola dumerili) associated with pelagic Sargassum in the NW Gulf of Mexico. Seriola dumerili were collected off Galveston, Texas, from May to July over a two-year period (2000 and 2001) in both inshore (<15 nautical miles [nmi]) and offshore zones (15−70 nmi). Relative abundance of YOY S. dumerili (32−210 mm standard length) from purse-seine collections peaked in May and June, and abundance was highest in the offshore zone. Ages of S. dumerili ranged from 39 to 150 days and hatching-date analysis indicated that the majority of spawning events occurred from February to April. Average daily growth rates of YOY S. dumerili for 2000 and 2001 were 1.65 mm/d and 2.00 mm/d, respectively. Intra-annual differences in growth were observed; the late-season (April) cohort experienced the fastest growth in both years. In addition, growth was significantly higher for S. dumerili collected from the offshore zone. Mortality was approximated by using catch-curve analysis, and the predicted instantaneous mortality rate (Z) of YOY S. dumerili was 0.0045 (0.45%/d)

Length-weight relationships of marine fishes from the central Brazilian coast

Parameters of the length-weight relationship are presented for 85 fish species from the marine and estuarine regions of the central Brazilian coast (latitude 13° to 23° S). Three different methods were used. A non-linear iterative process using the quasi-Newton algorithm yielded a better fit for all data sets analyzed. The length-weight allometry coefficient b estimated from standard length data tended to be lower than from total length data. The difference between these estimates was significant for some species

Length-weight relationships of marine fishes from the central Brazilian coast

Parameters of the length-weight relationship are presented for 85 fish species from the marine and estuarine regions of the central Brazilian coast (latitude 13° to 23° S). Three different methods were used. A non-linear iterative process using the quasi-Newton algorithm yielded a better fit for all data sets analyzed. The length-weight allometry coefficient b estimated from standard length data tended to be lower than from total length data. The difference between these estimates was significant for some species.Length-weight relationships, Marine fish, Stock assessment, Brazil,

The Effects of Fish Trap Mesh Size on Reef Fish Catch off Southeastern Florida

Catch and mesh selectivity of wire-meshed fish traps were tested for eleven different mesh sizes ranging from 13 X 13 mm (0.5 x 0.5") to 76 x 152 mm (3 X 6"). A total of 1,810 fish (757 kg) representing 85 species and 28 families were captured during 330 trap hauls off southeastern Florida from December 1986 to July 1988. Mesh size significantly affected catches. The 1.5" hexagonal mesh caught the most fish by number, weight, and value. Catches tended to decline as meshes got smaller or larger. Individual fish size increased with larger meshes. Laboratory mesh retention experiments showed relationships between mesh shape and size and individual retention for snapper (Lutjanidae), grouper (Serranidae), jack (Carangidae), porgy (Sparidae), and surgeonfish (Acanthuridae). These relationships may be used to predict the effect of mesh sizes on catch rates. Because mesh size and shape greatly influenced catchability, regulating mesh size may provide a useful basis for managing the commercial trap fishery

Effect of type of food and culture density on the rearing of Seriola dumerili

Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2013This thesis intended to study the effect of three different types of food and two different densities, on growth, survival, plasmatic parameters and lipid composition of muscle and liver of Seriola dumerili (Risso 1810) juveniles, in order to select an optimal feeding regime for growth, covering the nutritional requirements, and optimizing the commercial cost-effectiveness of the production. Regarding this, a total of 145 juvenile of Seriola dumerili with and average weight of 117.54 ± 54.98 g, were randomly distributed in 3 groups of 15 fish / tank (low stocking density LD) and 3 groups of 25 fish / tank (high stocking density HD) and fed with three different types of food: commercial pellets for Sparidae, the Alpha Biomar diet (SP), commercial pellets for S. dumerili (Skretting) (SE) and frozen Mackerel (MA). The study was conducted for 86 days. The study variables were the feeding regime and stocking density. The survival rates were higher in the groups fed with SE, while the Specific Growth Rate (SGR) showed no statistical differences (P>0.05) between groups. The groups fed with MA diet had the higher amounts of Daily Food Ingested (DFI), (9.59±3.56 g/fish at HD and 8.46±5.00 g/fish at LD) during the study, although with a higher Food Conversion Rate (FCR), (9.59 % at LD and 8.46 % at HD), not efficiently turn that ingestion in biomass, as for example the value of B% at groups fed with MA at LD (0.18 %) and at HD (-0.35%) show, being lower than the groups fed with SE at LD (0.41%). The biochemical composition of the fish in the present study was similar to the one reported in previous works, explaining that the more moisture content in the tissue, the less lipid it has in it. The Total Polar Lipids (TPL) and Total Neutral Lipids (TNL) did not show any significant differences (P0.05). Among the total neutral lipids (TNL), despite DAG, CHO and FFA were significantly different (P<0.05), TAG was the most abundant lipid class, which is generally the major lipid class in the diet of marine fish, and there was no significant differences (P<0.05) between the different groups. Regarding fatty acid composition, namely 18:1n-9, the groups fed with MA were the only significantly different (P<0.05), and the lowest amounts in this study (P<0.05), even taking in consideration that, in the wild, the S. dumerili diet is composed mainly by several finfish rich in 18:1n-9. We can deduce that or there was a degradation of the quality of the MA while stored to be fed to the groups, which affected directly the quality and quantity of the 18:1n-9. The fact that 18:2n-6 had its lower amounts in groups fed with MA, and the higher amounts in groups fed with SE (P<0.05), and taking in account that 18:2n-6 is the higher representative of n-6 fatty acid in diets, that is the fatty acid responsible for the most detrimental modifications to the fatty acid composition of cultured fish, suggest that this fatty acid is in excess in SE diet composition. The groups fed with MA presented the highest amounts of ARA (P<0.05) and the lower amounts of EPA (P<0.05), and the groups fed with SE presented the lower amounts of ARA and DHA (P<0.05). The lower amount of EPA and lower EPA/ARA ratio (P<0.05) found in groups fed with MA, could positively affect certain physiological functions. Due to the EPA and DHA competition for the same enzymes to esterify fatty acids into phospholipid structures, excessive accumulation of EPA could be prejudicial. In the groups fed with SE, the production of DHA was probably affected by it. The fact they had the lower amounts of ARA and DHA, inducing to a higher EPA/ARA ratio (P<0.05), suggests that the ratio is unbalanced and there is too much EPA accumulation, to insure ARA production Even though the group fed with MA at HD had the higher amount of DHA in this study (P<0.05), still the ratio DHA/ARA had no significant differences (P<0.05), indicating a stable balance between DHA and ARA amounts. This study suggests that the fatty acid profile of the different groups reflected the fatty acid composition of the diets, namely regarding 18:1n-9, 18:2n-6 and 20:5n-3, 20:4n-6 and 22:6n-3. that had effects in the ratios of DHA, EPA and ARA, affecting the balance between them, which had directly affected the growth. Regarding the plasma analysis, total protein was the only displaying statistical differences between diets and densities, and the fact that the groups fed with SE and MA diet, showed higher protein content, could be related to the fact those diets have higher protein levels (48g/l and 51.25 g/l respectively). From the present results it seems that the fatty acid composition of the pellets and frozen atlantic mackerel, affected the fatty lipid profile of S. dumerili, and so it development, so better balance between EFA diet composition while probably insure better energy efficiency and promoting growth. Considering the results obtained with SE, it seems to be the most appropriated for S. dumerili in the present study

Sobre la presència de dues espècies de peixos pelàgics associats a objectes flotants en el mar català (Mediterrània nordoccidental)

Abstract not availabl