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The short-scale temporal repeatability in the structure and composition of parasite communities of Nemadactylus bergi were analyzed by comparing population and infracommunity descriptors in five samples caught off Mar del Plata, Argentina (38º 27′ S, 57º 90′ W) at intervals of 20 days. This is the first study aiming to detect relevant local or short-term processes in an area where larval endohelminths dominate the parasite assemblages and are expected to provide predictability to the communities they belong. The parasite fauna of this host species was composed by 18 species, 16 of them being endoparasites, among which larval stages accounted for most of both the number of parasite individuals found and the highest percentages of average similarity among infracommunities. The structure of parasite communities of N. bergi was, as predicted, repeatable across samples at short spatial and temporal scales and, as expected, this predictability was mainly provided by larval stages, namely Corynosoma australe and Grillotia carvajalregorum. These results imply that a single sample of N. bergi from this locality will be enough to catch the structure and intrinsic variability of their component communities in further studies aiming to compare parasite assemblages at larger spatial scales. These studies should, however, take into account the heterogeneity in the size of fish among samples, which proved to be an important confounding factor in comparisons among samples by affecting their similarity. [ABSTRACT FROM AUTHOR]

A customized PCR-array was used for the simultaneous gene expression of the Gh/Igf system and related markers of muscle growth, and lipid and energy metabolism during early life stages of gilthead sea bream (60–127 days posthatching). Also, transcriptional reprogramming by mild hypoxia was assessed in fingerling fish with different history trajectories on O2 availability during the same time window. In normoxic fish, the expression of almost all the genes in the array varied over time with a prompted liver and muscle tissue-specific differentiation, which also revealed temporal changes in the relative expression of markers of the full gilthead sea bream repertoire of Gh receptors, Igfs and Igf-binding proteins. Results supported a different contribution through development of ghr and igf subtypes on the type of action of GH via systemic or direct effects at the local tissue level. This was extensive to Igfbp1/2/4 and Igfbp3/5/6 clades that clearly evolved through development as hepatic and muscle Igfbp subtypes, respectively. This trade-off is however very plastic to cope changes in the environment, and ghr1 and igfbp1/3/4/5 emerged as hypoxic imprinting genes during critical early developmental windows leading to recognize individuals with different history trajectories of oxygen availability and metabolic capabilities later in life. [ABSTRACT FROM AUTHOR]

Sobaity sea bream ( Sparidentex hasta) is distributed in the Western Indian Ocean, Persian Gulf and Oman Sea. For monitoring health status in this species in an aquaculture condition, standard reference values for haematological and plasma biochemical parameters are indispensable. Heparinized blood samples were collected from 143 healthy sobaity sea bream juveniles raised in cylindrical polyethylene tanks with filtered running seawater. Haematologic reference intervals were as follows: red blood cell (RBC) count 1.67-2.2 × 10 μL, total white blood cell (WBC) count 8.8-14.5 × 10 μL, lymphocytes 85-96 %, neutrophils 2-6 %, haemoglobin 28-60 g L, haematocrit (Hct) 24.5-33.8 %, mean cell volume (MCV) 126.3-191.7 fL, mean cell haemoglobin (MCH) 14.4-26.5 pg, mean cell haemoglobin concentration (MCHC) 92-180 g L, erythrocyte sedimentation rate (ESR) 1.5-5 mm h and RBC/WBC ratio 119.2-207.5. Plasma chemistry reference intervals were as follows: total protein 3.2-3.9 g dL, albumin 0.3-0.58 g dL, globulin 2.7-3.4 g dL, alkaline phosphatase 444-866 U L, alanine aminotransferase 239-506.5 U L, lipase 95.5-120 U L, amylase 4-8 U L, sodium 173-211 mmol L, chloride 103-136.5 mmol L, potassium 2.7-4.4 mmol L, calcium 2.6-3.1 mmol L, inorganic phosphorus 2.9-5.3 mmol L, osmolality 430-503 mOsm kg, glucose 6.16-7.88 mmol L, cholesterol 4.07-7.7 mmol L, triglyceride 2.22-3.91 mmol L, high-density lipoprotein (HDL) 1.36-2.44 mmol L, low-density lipoprotein (LDL) 0.84-1.19 mmol L and very-low-density lipoprotein (VLDL) 0.27-0.78 mmol L. Values reported here will be useful for evaluating the health status, interpretation and better understanding of various disease signs in sobaity sea bream juveniles. [ABSTRACT FROM AUTHOR]

The technology of floating sea cages that is largely used in the Mediterranean aquaculture provides optimal conditions for the development of marine fouling. The present study investigates the influence of micro-fouling developed on a net, on sea bream behavior. Negative effects of biofouling were not tested since the study was performed under laboratory conditions and for short experimental period. The net condition (micro-fouling filaments) is further examined in comparison with a similar green-brown colored and a white net pen. From the results obtained, it can be concluded that micro-fouling filaments highly induce net biting. In contrast, the colored net tested in this study negatively affected sea bream interactions on the net. Results lead to the conclusion that the fouling filaments are more important to sea bream attraction than the net color, while both variables affect species behavior. [ABSTRACT FROM AUTHOR]

We surveyed the distribution of red sea bream eggs between 2006 and 2010 in the east Seto Inland Sea to determine the location of the spawning grounds and the characteristics of preferred spawning habitats. We identified early-development stage red sea bream eggs using a monoclonal antibody assay. The early-development stage eggs were present in waters around Awaji Island (AW area) and around Ieshima Island, Shodo Island, and Bisan Seto (collectively the ISB area). The mean red sea bream egg density in the AW area was not significantly different from that in the ISB area. Based on the locations where we observed early-development stage eggs and the density of eggs, the ISB and AW areas appeared to be the primary spawning grounds in the east Seto Inland Sea during the survey period. A quotient analysis suggested that spawning fish had clear preferences for physical conditions. The areas suitable for spawning appear to be those with sandy substrate at a depth of 30-70 m. The temperature range suitable for spawning was between 16.5 and 21.5 °C. [ABSTRACT FROM AUTHOR]

Four previously unrecognized trypanorhynchids are described based on fish specimens from Sparidae and Mullidae host fish of the Red Sea. From September 2010 to June 2011, 66 specimens of the sea bream Pagrus pagrus (F: Sparidae) and 43 of the red mullet Mullus barbatus (F: Mullidae) were purchased from markets in the Suez and Hurghada cities of the Red Sea. The fishes were measured, and their organs investigated for helminth infections. Forty-one (37.6 %) out of the 109 fish specimens investigated were parasitized with Trypanorhyncha metacestodes, identified as Callitetrarhynchus speciouses Linton 1897, Pseudogrillotia sp. Dollfus , Kotorella pronosoma Stossich from P. pagrus, and Nybelinia bisulcata Linton 1889 from M. barbatus in the mesentery and peritoneal cavity, with prevalences of 16.5, 11.0, 6.0, and 12.0 %. All of these larval stages were encapsulated larvae in blastocysts. C. speciouses is characterized by an elongated scolex, two bothria, a long postbulbosa, and four elongated bulbs. Pseudogrillotia sp. possesses a scolex with two lateral patelliform bothridia; posterior margins are free, not notched. A long sheath was observed, which was irregularly coiled when tentacles invaginated. N. bisulcata possesses an acraspedote scolex with four bothridia, which are broad, bean-shaped. The tentacles are spirally coiled, supplied with hooks with abruptly turned points. The four tentacles sheaths rose from scolex as two anterior (front) and two posterior (back) which overlap at the apices of bulbs. K. pronosoma is characterized by a short body with a craspedote scolex and four bothridia. The tentacles are short and emerge pairwise. The presence of Trypanorhyncha metacestodes in the muscles does not represent a risk of infection for humans. They have a negative effect on fish esthetics. The repugnant aspect and the prohibition for commercial use by sanitary inspectors, however, cause consumer rejection. Parasites of the order Trypanorhyncha have been recorded in these host fishes for the first time. [ABSTRACT FROM AUTHOR]

A comparative study of the effects of different doses (2.5 and 5.0 kGy) of gamma radiation on the formation of 12 biogenic amines and ammonia during the storage of sea bream ( Sparus aurata) in ice was carried out. No significant differences in ammonia content were observed among the groups, except for 17 days of storage ( p > 0.05). Although 12 biogenic amines were determined by HPLC, histamine, tyramine and 2-phenylethylamine were not detected. The main amines formed in sea bream muscle were trimethylamine, putrescine and cadaverine, respectively. Dopamine, serotonin and spermidine concentration remained below the value of 0.6 mg/100 g and did not change significantly for all groups during storage periods ( p > 0.05). However, irradiation led to a minor increase in spermine, agmatine and tryptamine concentrations of sea bream in some storage days. The radiation dose used had similar effects on reducing biogenic amine content, except for agmatine, tryptamine. [ABSTRACT FROM AUTHOR]

To determine the effects of sustained swimming on the use and fate of dietary nutrients in gilthead sea bream, a group of fish were forced to undertake moderate and sustained swimming (1.5 BL s) for 3 weeks and compared with a control group undertaking voluntary activity. The exercise group showed a significant increase in specific growth rate (C: 1.13 ± 0.05; E: 1.32 ± 0.06 % day, P < 0.05) with no significant change in food intake (C: 3.56 ± 0.20; E: 3.84 ± 0.03 % of body weight). The addition of C-starch and N-protein to a single meal of 1 % ration allowed analysis of the fate of both nutrients in several tissues and in their components, 6 and 24 h after force-feeding. In exercised fish improved redistribution of dietary components increased the use of carbohydrates and lipid as fuels. Gilthead sea bream have a considerable capacity for carbohydrate absorption irrespective of swimming conditions, but in trained fish C rose in all liver fractions with no changes in store contents. This implies higher nutrient turnover with exercise. Higher retention of dietary protein (higher N uptake into white muscle during the entire post-prandial period) was found under sustained exercise, highlighting the protein-sparing effect. The combined effects of a carbohydrate-rich, low-protein diet plus sustained swimming enhanced amino acid retention and also prevented excessive lipid deposition in gilthead sea bream. [ABSTRACT FROM AUTHOR]

The tolerance of fish to fasting offers a model to study the regulatory mechanisms and changes produced when feeding is restored. Gilthead sea bream juveniles were exposed to a 21-days fasting period followed by 2 h to 7-days refeeding. Fasting provoked a decrease in body weight, somatic indexes, and muscle gene expression of members of the Gh/Igf system, signaling molecules (akt, tor and downstream effectors), proliferation marker pcna, myogenic regulatory factors, myostatin, and proteolytic molecules such as cathepsins or calpains, while most ubiquitin-proteasome system members increased or remained stable. In bone, downregulated expression of Gh/Igf members and osteogenic factors was observed, whereas expression of the osteoclastic marker ctsk was increased. Refeeding recovered the expression of Gh/Igf system, myogenic and osteogenic factors in a sequence similar to that of development. Akt and Tor phosphorylation raised at 2 and 5 h post-refeeding, much faster than its gene expression increased, which occurred at day 7. The expression in bone and muscle of the inhibitor myostatin (mstn2) showed an inverse profile suggesting an inter-organ coordination that needs to be further explored in fish. Overall, this study provides new information on the molecules involved in the musculoskeletal system remodeling during the early stages of refeeding in fish. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the economic effect of the red sea bream Pagrus major offshore aquaculture production system in Korea. Based on the data collected, revenue and expenses throughout the culture period were calculated, and the net present value and internal rate of return of the ten-year cash flow and cash outflow were estimated in order to determine the economic validity of red sea bream offshore aquaculture production. Results showed that the red sea bream offshore aquaculture production system had high profitability based on the current production and market conditions. This is because of its relatively high survival rate, relatively low feed conversion ratio, and good market price level. However, sensitivity analyses of the main variables indicated that the profitability of red sea bream offshore aquaculture is highly vulnerable to production conditions and market condition changes. [ABSTRACT FROM AUTHOR]

Escape of fish is a significant problem for the sustainability of the aquaculture industry. In the Mediterranean Sea, sea bream ( Sparus aurata) has been reported to escape from sea cage installations. However, the related factors leading to this behavior still remain unknown. This study focuses on the impact that the food supplied to sea bream has on its interaction with the net and therefore its escape behavior. We test three food ratios (2, 1 and 0 % of the total initial body weight; FC2, FC1 and FC0 populations, respectively) and three different conditions of the net (flawless mesh, mesh with a cut twine and mesh with a tear) that are commonly found in aquaculture. Data acquisition and analysis are carried out with a tailor-made system developed in our laboratory for this purpose. We demonstrate that food supply is associated with fish interactions and the aquaculture net, while net condition is also an important stimulus for sea bream inspection and biting the net. Limited-fed fish (FC1) are more prone to interact with the net, which consequently leads them to either bite net wears or escape through tears. [ABSTRACT FROM AUTHOR]

Sea bream ( Sparus aurata) production plays a significant part in Italian aquaculture, contributing to almost 18% of national pisciculture sales revenue. In recent years, Italian firms faced higher competition from countries with lower production costs. This prompted responses toward both cost reduction and product differentiation. The objective of this study was to investigate the preferences of Italian consumers for sea bream from fish farms, with a focus on aspects of product differentiation as gleaned from the analysis of the market situation: price, product origin, type and place of fish farming, and, in particular, type of feed. Data were collected with a consumers' survey using personal interviews conducted on a questionnaire that included a choice experiment. Consumer preferences were analyzed with choice models based on stated preference data. The models made it possible to evaluate the potential of products with different combinations of attributes for which there is currently no market information available. In particular, the country of origin emerged as an important element of consumer choice, and to a lesser degree, organic certification and fish farming in marine cages also play a relevant role and may command a price premium. [ABSTRACT FROM AUTHOR]

The preservative effect of laurel ( Laurus nobilis) and cumin ( Cuminum cyminum) essential oils (EOs) on fresh vacuum-packed (VP) wild and farmed sea bream ( Sparus aurata) fillets was evaluated during ice storage by microbiological, physicochemical and electrophoretic analyses. In the present study, wild (W) and farmed (F) fillet treatment included the following lots: control vacuum-packaged samples (WV and FV), VP with added EOs (0.5% v/ w) of cumin (WVC and FVC), and of laurel (WVL and FVL). Wild and cultured fish were found to differ significantly in their muscle proximate compositions irrespective of fillet treatments with particularly higher fat and carbohydrate contents in farmed sea bream (4.82 and 0.32 g/100 g, respectively, vs. 1.53 and 0.22 g/100 g in wild fish). The treatment of wild and farmed sea bream fillets with laurel or with cumin EOs induced a decrease in bacterial growth by ca. 0.5 to 1 log cfu/g and in lipid oxidation by ca. 40% of TBA value, extending the shelf life of fish fillets by approximately 5 days of ice storage. However, the addition of EOs to VP fillets resulted in a reduced liquid holding capacity (LHC) throughout ice storage suggesting an early proteolysis initiation confirmed by the myofibrillar and sarcoplasmic electrophoretic profiles. Laurel and cumin EOs as natural and efficient antibacterial and antioxidant compounds can be used in conjunction with VP to enhance ice-stored sea bream quality. [ABSTRACT FROM AUTHOR]

The article offers information on sesquiterpene derivates and steroids from the sponges of Dactylospongia elegans, which is widely studied for their biologically active compounds, from the South China Sea. It is noted that sesquiterpene quinones and its derivatives constitute cytotoxic natural products from sponges. Some of these derivatives are Dactyltronic Acids, Polyfibrospongol A and Dictyoceratin C.

It is known that responses to the same anesthetic can vary considerably among different fish species. In this investigation, the efficacy of two anesthetic agents (clove powder and 2-phenoxyethanol) was compared in Sobaity sea bream, Sparidentex hasta (Valenciennes 1830). Induction and recovery times for S. hasta anesthetized with anesthetic agents were dose-dependent ( P < 0.05). The onset of individual phases of anesthesia and recovery times depended significantly on the concentration of the anesthetic used ( P < 0.05). An inverse exponential relationship was observed between concentrations of anesthetic and induction time, whereas exponential relationships were observed between concentrations and recovery times for both anesthetic agents evaluated. The lowest effective concentrations based on the efficacy criteria of complete anesthetic induction within 180 s and recovery within 300 s were determined to be 100 mg L (induction time 1.92 ± 0.10 min and recovery time 2.48 ± 0.17 min) for clove powder and 200 μL L (induction time 2.55 ± 0.14 min and recovery time 5.66 ± 0.62 min) for 2-phenoxyethanol. Clove powder was proven to be more effective, and the latter appears to meet many of the criteria of an ideal anesthetic for this fish species. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the seasonal cellular stress response in vital organs, like the heart, the liver, the whole blood and the skeletal (red and white) muscles of the Mediterranean fish Sparus aurata during a 1-year acclimatization period in the field, in two examined depths (0-2 m and 10-12 m). Processes studied included heat shock protein expression and protein kinase activation. Molecular responses were addressed through the expression of Hsp70 and Hsp90, the phosphorylation of stress-activated protein kinases and particularly p38 mitogen-activated protein kinase (p38 MAPK), the extracellular signal-regulated kinases (ERK-1/2) and c-Jun N-terminal kinases (JNK1/2/3). The induction of Hsp70 and Hsp90 and the phosphorylation of p38 MAPK, JNKs and ERKs in the examined five tissues of the gilthead sea bream indicated a cellular stress response under the prism of a seasonal pattern which was characterized by distinct tissue specificity. Specifically, Hsp induction and MAPK activation occurred before peak summer water temperatures, with no further increases in their levels despite increases in water temperatures. Moreover, although water temperature did not vary significantly with depth of immersion, significant effects of depth on cellular stress response were observed, probably caused by different light regime. The expression and the activation of these certain proteins can be used as tools to define the extreme thermal limits of the gilthead sea bream. [ABSTRACT FROM AUTHOR]

The amino acid composition and protein levels of three species of cephalopods ( Octopus vulgaris, Loligo gahi and Todarodes sagittatus), the natural diets of common octopus ( O. vulgaris) and different kinds of meals were determined in order to optimise the content of these nutrients in artificial feeds. Arginine, leucine and lysine were the most abundant essential amino acids in cephalopods, while glutamate and aspartate represented the main non-essential amino acids. Arginine and leucine were the limiting amino acid in most samples, with maximum Chemical Score values for mussel (79-98 %), squid (84 %) and crustaceans (65-91 %); medium for fish (41-70 %); and minimum for meals (29-64 %). Mussel, squid, crustaceans and fish showed a high essential amino acid index according to Oser (OI: 88-99 %) suggesting a suitable amino acid balance. The protein from animal meals (fish and krill) covered all the essential amino acids except arginine and lysine in fish meal. The vegetable meal presented the worst amino acid balance (OI: 74-89 %) with several deficiencies in essential amino acids, including arginine, threonine, lysine and methionine. Supplementation with arginine or leucine and protein complementation of crustaceans and bivalves with fish or animal meal are proposed as alternatives for improving the performance of protein in feed for cephalopods. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the role of soluble non-starch polysaccharide (guar gum) on white sea bream Diplodus sargus, glucose and lipid metabolism. A control diet was formulated to contain 40 % crude protein, 14 % crude lipids and 35 % pregelatinized maize starch, and three other diets were formulated similar to the control diet except for guar gum, which was included at 4 % (diet GG4), 8 % (diet GG8) or 12 % (diet GG12). Diets were fed to the fish for 9 weeks on a pair-feeding scheme. Guar gum had no effect on growth performance, feed efficiency, glycaemia, cholesterolaemia and plasma triacylglyceride levels. Hepatic glucokinase and pyruvate kinase activities, liver glycogen content and liver insulin-like growth factor-I gene expression were not affected by dietary guar gum, while fructose-1,6-bisphosphatase activity was lower in fish fed guar gum-supplemented diets. Hepatic glucose-6-phosphate dehydrogenase activity was higher in fish fed diets GG4 and GG8 than in the control group. Overall, data suggest that in contrast to mammals guar gum had no effect on white sea bream glucose utilization and in lowering plasma cholesterol and triacylglyceride levels. However, it seems to contribute to lower endogenous glucose production. [ABSTRACT FROM AUTHOR]

In the marine fish intestine luminal, HCO can remove divalent ions (calcium and magnesium) by precipitation in the form of carbonate aggregates. The process of epithelial HCO secretion is under endocrine control, therefore, in this study we aimed to characterize the involvement of transmembrane (tmACs) and soluble (sACs) adenylyl cyclases on the regulation of bicarbonate secretion (BCS) and water absorption in the intestine of the sea bream ( Sparus aurata). We observed that all sections of sea bream intestine are able to secrete bicarbonate as measured by pH-Stat in Ussing chambers. In addition, gut sac preparations reveal net water absorption in all segments of the intestine, with significantly higher absorption rates in the anterior intestine that in the rectum. BCS and water absorption are positively correlated in all regions of the sea bream intestinal tract. Furthermore, stimulation of tmACs (10 μM FK + 500 μM IBMX) causes a significant decrease in BCS, bulk water absorption and short circuit current (Isc) in a region dependent manner. In turn, stimulation of sACs with elevated HCO results in a significant increase in BCS, and bulk water absorption in the anterior intestine, an action completely reversed by the sAC inhibitor KH7 (200 μM). Overall, the results reveal a functional relationship between BCS and water absorption in marine fish intestine and modulation by tmACs and sAC. In light of the present observations, it is hypothesized that the endocrine effects on intestinal BCS and water absorption mediated by tmACs are locally and reciprocally modulated by the action of sACs in the fish enterocyte, thus fine-tuning the process of carbonate aggregate production in the intestinal lumen. [ABSTRACT FROM AUTHOR]

A study was carried out with gilthead sea bream juveniles to assess the effect of water temperature (18 and 25°C) and dietary pregelatinized starch level (10, 20 and 30%) on digestibility of protein and starch and on the activity of proteolytic and amylolytic enzymes. ADC of pregelatinized starch was very high (>99%) irrespectively of dietary inclusion level, and it was not affected by water temperature. ADC of protein was also high (>90%) but improved at the higher water temperature. Dietary starch interacted with protein digestibility, which decreased as dietary starch level increased. Temperature affected both acid and basic protease activities, with acid protease activity being higher at 25°C and basic protease activity being higher at 18°C. However, total proteolytic activity and amylase activities were not affected by water temperature. Dietary carbohydrate exerted no effect on proteolytic or amylolitic activities. It is concluded that gilthead sea bream juveniles digest pregelatinized starch very efficiently irrespective of water temperature, due to adjustments of amylase activity to cope with temperature differences. Pregelatinized starch interacts negatively with protein digestibility, with the ADC of protein decreasing as dietary starch levels increase. [ABSTRACT FROM AUTHOR]

A glucose tolerance test was performed in white sea bream Diplodus sargus, juveniles to evaluate the effect of a glucose load on plasma glucose, insulin, triacylglyceride levels, and on liver glycogen storage in order to study the capability of glucose utilization by this species. After being fasted for 48 h, fish were intraperitoneally injected with either 1 g of glucose per kg body weight or a saline solution. Plasma glucose rose from a basal level of 4 to a peak of 18-19 mmol l, 2-4 h after glucose injection and fish exhibited hyperglycemia for 9 h. An insulin peak (from 0.5 to 0.8 ng ml) was observed 2-6 h after glucose injection, and basal value was attained within 9 h. Liver glycogen peaked 6-12 h after the glucose load and thereafter decreased to the basal value which was attained 24 h after injection. Plasma triacylglycerides in glucose-injected fish were only significantly higher than the basal value 12 h after injection. Glucose-injected fish generally showed lower plasma triacylglyceride levels than control fish. Our results indicate that under these experimental conditions, glucose acts as an insulin secretagogue in white sea bream juveniles. Moreover, insulin may have contributed to restoring basal plasma glucose levels by enhancing glucose uptake in the liver. Further studies are needed to corroborate the lipolytic action of glucose. Clearance of glucose from the blood stream was fast, comparatively to other species, indicating that white sea bream has a good capability of glucose utilization. [ABSTRACT FROM AUTHOR]

After the development of the gastric function in juvenile fish, dietary proteins enter a two-phase digestive process comprising an acidic gastric phase followed by an alkaline intestinal phase. However, the main gastric protease, pepsin, is strictly dependent on the existence of a low-enough environmental pH. In 20-g gilthead sea bream, Sparus aurata, the mean minimal gastric pH is close to 4.5, while the mean pH in the duodenal portion of the intestine was nearly fixed at 6.5. The mean maximal gastric content of HCl was approximately 20 microEq for a low-buffering diet. Gastric proteases were more severely affected than intestinal proteases when assayed at actual sub-optimal pH values, 4.5 and 6.5, respectively. When the gastric proteases of juvenile fish were pre-incubated with a citric acid buffer at pH 6.0, the activity at pH 4.5 was very low, whereas when they were pre-incubated with the same buffer at pH 3.0, the activity at pH 4.5 was significantly increased; this fact suggests a deficient activation of zymogens during the gastric digestion and points to a potential approach to improve protein digestion in juvenile gilthead sea bream. [ABSTRACT FROM AUTHOR]

The following lepocreadiid species are described from Cheilodactylidae from south-western Australia. Cliveus peroni n. g., n. sp. from Nemadactylus valenciennesi is characterised by its attenuated forebody and C. acaenodera n. sp. from Dactylophora nigricans by its attenuated forebody, the pattern of forebody spination and the large cirrus-sac. Jericho chojeri n. g., n. sp. from N. valenciennesi has a large infundibuliform oral sucker and paired ani. Rugocavum n. g. is distinguished by the possession of a blind, wrinkled glandular pit on the postero-ventral surface of the forebody. R. nemadactyli n. sp. from N. valenciennesi has its vitelline field restricted to the hindbody, whereas in R. morwong n. sp. from N. valenciennesi the vitelline field reaches into the forebody. Paraneocreadium australiense Kruse, 1978 from N. valenciennesi is redescribed and its coiled internal seminal vesicle and lobed gonads are considered distinctive features. Scaphatrema nemadactyli (Kurochkin & Korotaeva, 1972) n. g., n. comb. from N. valenciennesi has a wrinkled, boat-shaped body, a ‘Lepidapedon-like’ cirrus-sac and multiple testes; it was originally placed in the genus Multitestis, but these characters suggest that a new genus should be erected for it within the subfamily Lepidapedinae. [ABSTRACT FROM AUTHOR]

Acanthocephalans display a two-host life cycle that involves arthropods as intermediate hosts and vertebrates as definitive hosts. Some species also use paratenic hosts to bridge the trophic gap between both obligatory hosts. However, the relative role of these paratenic hosts in the transmission to definitive hosts has seldom been assessed quantitatively. We report on infection patterns of cystacanths of Corynosoma australe Johnston, 1937 in 20 common teleost species and the Argentine shortfin squid Illex argentinus (Castellanos) from the Patagonian shelf of Argentina. We also explore the role of different fish species in the transmission of C. australe to the most important definitive host in the area, i.e. the South American sea lion Otaria flavescens Shaw. Cystacanths of C. australe were found in all host species except Heliconus lahillei Norman, Merluccius hubbsi Marini and I. argentinus. In eight fish species, the prevalence of C. australe was > 50% and mean intensity > 4, i.e. Acanthistius patachonicus (Jenyns), Nemadactylus bergi (Norman), Paralichthys isosceles Jordan, Percophis brasiliensis Quoy & Gaimard, Prionotus nudigula Ginsburg, Scomber colias Gmelin, Raneya brasiliensis (Kaup) and Xystreurys rasile (Jordan). Two surveys on the trophic ecology of South American sea lions in the study area consistently found a generalist diet dominated by M. hubbsi, and data on the frequency of occurrence and number of other fish and cephalopod species in stomach contents strongly suggest that only R. brasiliensis may play a prominent role in the transmission of C. australe. This result raises interesting questions on the costs of paratenicity. [ABSTRACT FROM AUTHOR]

Pycnadenoides pagrosomi Yamaguti, 1938 and P. reversati n. sp. from Pagrus auratus (Sparidae) and P. invenustus n. sp. from Nemadactylus valenciennesi (Cheilodactylidae) are described from the temperate marine waters off south-west Western Australia and south-east Queensland. The difference in the anterior extent of the vitelline follicles observed in P. reversati n. sp. recovered from off south-east Queensland waters and the material from off Western Australia is discussed. P. reversati n. sp. is distinguished from P. pagrosomi mainly in the position of the genital pore and in the arrangement of the testes, and from P. invenustus n. sp. in the posterior extent of the cirrus-sac. P. reversati belongs to the group of species with a short cirrus-sac and P. invenustus to the group with the cirrus-sac reaching into the anterior hindbody. [ABSTRACT FROM AUTHOR]

Focuses on a study which investigated the impact of specimen handling on concentration of elements found in fish otoliths. Identification of the fish otoliths; Detection of the elements by electron-probe microanalysers; Methodology used to conduct the study; Results of the study.

A new genus and species of the Hatschekiidae, Laminohatschekia synaphobranchi, is described from an eel caught off New Caledonia. It is characterised by its long ribbon-like trunk and by the possession of three pairs of biramous legs. The pennellid Sarcotretes scopeli is redescribed from a macrourid also taken off New Caledonia. Sarcotretes lobatus is recognised as a synonym of S. scopeli. Phrixocephalus carcellesi is described in detail for the first time, from the stomach contents of a King Shag caught in the Falkland Islands. A wide range of individual variability in holdfast structure was noted in P. carcellesi. A new species, Peniculisa bellwoodi, is described from Pomacentrus amboiensis collected at Lizard Island on the Great Barrier Reef. The sphyriid Lophoura cornuta is redescribed from a synaphobranchid eel caught off New Caledonia and both sexes of a lernanthropid, Aethon morelandi, are redescribed from Nemadactylus macropterus in southern Australia. [ABSTRACT FROM AUTHOR]

A common goal among fisheries science professionals, stakeholders, and rights holders is to ensure the persistence and resilience of vibrant fish populations and sustainable, equitable fisheries in diverse aquatic ecosystems, from small headwater streams to offshore pelagic waters. Achieving this goal requires a complex intersection of science and management, and a recognition of the interconnections among people, place, and fish that govern these tightly coupled socioecological and sociotechnical systems. The World Fisheries Congress (WFC) convenes every four years and provides a unique global forum to debate and discuss threats, issues, and opportunities facing fish populations and fisheries. The 2021 WFC meeting, hosted remotely in Adelaide, Australia, marked the 30th year since the first meeting was held in Athens, Greece, and provided an opportunity to reflect on progress made in the past 30 years and provide guidance for the future. We assembled a diverse team of individuals involved with the Adelaide WFC and reflected on the major challenges that faced fish and fisheries over the past 30 years, discussed progress toward overcoming those challenges, and then used themes that emerged during the Congress to identify issues and opportunities to improve sustainability in the world's fisheries for the next 30 years. Key future needs and opportunities identified include: rethinking fisheries management systems and modelling approaches, modernizing and integrating assessment and information systems, being responsive and flexible in addressing persistent and emerging threats to fish and fisheries, mainstreaming the human dimension of fisheries, rethinking governance, policy and compliance, and achieving equity and inclusion in fisheries. We also identified a number of cross-cutting themes including better understanding the role of fish as nutrition in a hungry world, adapting to climate change, embracing transdisciplinarity, respecting Indigenous knowledge systems, thinking ahead with foresight science, and working together across scales. By reflecting on the past and thinking about the future, we aim to provide guidance for achieving our mutual goal of sustaining vibrant fish populations and sustainable fisheries that benefit all. We hope that this prospective thinking can serve as a guide to (i) assess progress towards achieving this lofty goal and (ii) refine our path with input from new and emerging voices and approaches in fisheries science, management, and stewardship. [ABSTRACT FROM AUTHOR]

Marine population modeling, which underpins the scientific advice to support fisheries interventions, is an active research field with recent advancements to address modern challenges (e.g., climate change) and enduring issues (e.g., data limitations). Based on discussions during the 'Land of Plenty' session at the 2021 World Fisheries Congress, we synthesize current challenges, recent advances, and interdisciplinary developments in biological fisheries models (i.e., data-limited, stock assessment, spatial, ecosystem, and climate), management strategy evaluation, and the scientific advice that bridges the science-policy interface. Our review demonstrates that proliferation of interdisciplinary research teams and enhanced data collection protocols have enabled increased integration of spatiotemporal, ecosystem, and socioeconomic dimensions in many fisheries models. However, not all management systems have the resources to implement model-based advice, while protocols for sharing confidential data are lacking and impeding research advances. We recommend that management and modeling frameworks continue to adopt participatory co-management approaches that emphasize wider inclusion of local knowledge and stakeholder input to fill knowledge gaps and promote information sharing. Moreover, fisheries management, by which we mean the end-to-end process of data collection, scientific analysis, and implementation of evidence-informed management actions, must integrate improved communication, engagement, and capacity building, while incorporating feedback loops at each stage. Increasing application of management strategy evaluation is viewed as a critical unifying component, which will bridge fisheries modeling disciplines, aid management decision-making, and better incorporate the array of stakeholders, thereby leading to a more proactive, pragmatic, transparent, and inclusive management framework–ensuring better informed decisions in an uncertain world. [ABSTRACT FROM AUTHOR]

Marine species will respond to climate change through distributional shifts to follow suitable habitats in the future. Here, we predicted the future potential global distribution of commercial fishes and shrimps using the MaxEnt modeling technique under future RCP scenarios. In total, 3741 geographical records of commercial fishes and shrimps were collected from online databases including GBIF (42%), OBIS (19%), literature (31%), and personal spatial records (8%) from Aug 2021 to Feb 2022. Our finding indicated values AUC (the average area under the curve) > 0.9 for all species showing the high performance of MaxEnt in predicting the actual distribution of species. Depth (57%) and sea-surface temperature (34%) were the most powerful environmental predictors in the future distribution of all species. Higher dominance of habitats with high suitability was observed for shrimps (36%) compared to fishes (14%). In all species, habitats with high suitability would be decreased until 2100 with a rate of 8–16% and 4–12% for fishes and shrimps, respectively. The Persian Gulf, coasts of North, East and West of Australia, and North of the Arabian Sea would be suitable habitats for species under future scenarios. The model predicted that 3 species (60%) will expand in their future distribution ranges with poleward shifting from 39 to 2188 km and the remaining (40%) will shrink in distribution ranges from 176 to 1260 km in the future. The findings highlighted the vulnerability of commercial fishes and shrimps under future climate changes and confirmed the prominent role of temperature in the redistribution of commercial fishes and shrimps to follow suitable habitats toward higher latitudes in the future. [ABSTRACT FROM AUTHOR]

Climate change impacts on fishery resources have been widely reported worldwide. Nevertheless, a knowledge gap remains for the warm-temperate Southwest Atlantic Ocean—a global warming hotspot that sustains important industrial and small-scale fisheries. By combining a trait-based framework and long-term landing records, we assessed species' sensitivity to climate change and potential changes in the distribution of important fishery resources (n = 28; i.e., bony fishes, chondrichthyans, crustaceans, and mollusks) in Southern Brazil, Uruguay, and the northern shelf of Argentina. Most species showed moderate or high sensitivity, with mollusks (e.g., sedentary bivalves and snails) being the group with the highest sensitivity, followed by chondrichthyans. Bony fishes showed low and moderate sensitivities, while crustacean sensitivities were species-specific. The stock and/or conservation status overall contributed the most to higher sensitivity. Between 1989 and 2019, species with low and moderate sensitivity dominated regional landings, regardless of the jurisdiction analyzed. A considerable fraction of these landings consisted of species scoring high or very high on an indicator for potential to change their current distribution. These results suggest that although the bulk of past landings were from relatively climate-resilient species, future catches and even entire benthic fisheries may be jeopardized because (1) some exploited species showed high or very high sensitivities and (2) the increase in the relative representation of landings in species whose distribution may change. This paper provides novel results and insights relevant for fisheries management from a region where the effects of climate change have been overlooked, and which lacks a coordinated governance system for climate-resilient fisheries. [ABSTRACT FROM AUTHOR]

The snakehead gudgeon, Giuris laglaizei, is a native species in the Philippines. Recently, this fish was also reported in Indonesia. This species is exploited for use as food and in some localities, even the fry are harvested in large numbers. In this study, the genetic diversity of six lacustrine populations of the species in the Philippines was examined based on the 852-bp full-length sequence of the mitochondrial DNA control region (mtDNA CR). A total of 107 haplotypes were recovered from 182 mtDNA CR sequences. High levels of nucleotide and haplotype diversities were found for the populations in Lake Mainit, Lake Taal, and Lake Naujan. The populations in Lake Lanao, Laguna de Bay, and Lake Paoay had high levels of haplotype diversity, but low levels of nucleotide diversity. The median-joining network showed geographic separation of the northern populations (Laguna de Bay, Taal, Naujan, and Paoay) from the southern populations (Lanao and Mainit). Pairwise FST value was lowest and non-significant (FST = 0.013; P = 0.149) between the populations from lakes Lanao and Mainit. This provides genetic support to previous claims that G. laglaizei in Lake Lanao came from Lake Mainit. On the other hand, significant genetic differentiation that ranged from moderate to very large (FST = 0.079–0.434) was detected among the northern populations. Despite the overall high levels of genetic diversity detected in this study, like any fishery resource, G. laglaizei still merits conservation and fishery management plans for sustainable harvest and to ensure the maintenance of high levels of genetic diversity. [ABSTRACT FROM AUTHOR]

This paper presents a collection of environmental, geophysical, and other marine-related data for marine ecological models and ecological-niche models. It consists of 2132 raster data for 58 distinct parameters at regional and global scales in the ESRI-GRID ASCII format. Most data originally belonged to open data owned by the authors of this article but residing on heterogeneous repositories with different formats and resolutions. Other data were specifically created for the present publication. The collection includes 565 data with global scale range; 154 at 0.5° resolution and 411 at 0.1° resolution; 196 data with annual temporal aggregation over ~10 key years between 1950 and 2100; 369 data with monthly aggregation at 0.1° resolution from January 2017 to ~May 2021 continuously. Data were also cut out on 8 European marine regions. The collection also includes forecasts for different future scenarios such as the Representative Concentration Pathways 2.6 (63 data), 4.5 (162 data), and 8.5 (162 data), and the A2 scenario of the Intergovernmental Panel on Climate Change (180 data). Measurement(s) habitat similarity • Time Series Analysis • Principal Component Technology Type(s) Habitat Representativeness Score • Cross-Correlation • Principal Component Analysis Factor Type(s) Sea-bottom and sea-surface dissolved oxygen, salinity, and temperature • Sea net primary production • Sea ice concentration • Average, minimum, maximum sea depth • Average, minimum, maximum elevation • Distance of a square marine area from land and its fraction covered by water • Indication of the belonging Large Marine Ecosystem (LME), Exclusive Economic Zone (EEZ), Marine Ecoregions of the World (MEOW), Major Ocean Basins, and Marine Protected Area (MPA) • Number of islands • Water area that lies within the shelf, slope, and abyssal zones • Tidal range extension • Coral density • Estuary and seamount presence • Carbon dioxide flux at soil • Air surface temperature • Precipitation • Difference between air surface temperature and sea surface temperature • World population density • Sediment thickness • Atmospheric concentration of methane and nitrous oxide • Earth heat flow • Distance from crust plates • Earthquake density, depth, magnitude • Groundwater resources Sample Characteristic - Environment climate system Sample Characteristic - Location Oceans and Seas • Adriatic Sea • Aegean Sea • Baltic Sea • Bay of Biscay • Black Sea • Mediterranean Sea, Eastern Basin • North Sea • Mediterranean Sea, Western Basin [ABSTRACT FROM AUTHOR]

Many seabirds show sexual differences in different aspects of their trophic ecology. The Imperial Cormorant (Leucocarbo atriceps) presents sexual size dimorphism, with males being larger and heavier than females. They show sexual differences in feeding behaviour, but no studies have yet comprehensively quantified the sexual segregation in the use of food resources. Diet composition through the analysis of stomach content samples and isotopic niches of female and male individuals were assessed during the incubation and chick rearing stage of 2019 at Islas Blancas (44°46′S, 65°38′W) and Punta León (43°04′S, 64°29′W), Argentina. A total of 117 stomach content samples and 80 whole blood samples were analysed. The sexes differed significantly in their overall prey composition. Females consumed mostly benthic prey in all cases, while males consumed demersal, pelagic or benthic prey depending on the breeding stage and colony. Males presented a lower diet diversity and consumed larger prey items than females in all stages. The isotopic niche of females and males differed in position and/or amplitude, presenting variations in the axes, in agreement with the results based on conventional diet analysis. Females and males exhibited trophic resource partitioning, although patterns of segregation varied depending on the stages of the breeding cycle and the location of the colony. These patterns show the differential role of the sexes in marine food webs, and may expose females and males to different environmental and anthropogenic pressures. [ABSTRACT FROM AUTHOR]

Understanding how marine food webs are affected by anthropogenic stressors is an important steppingstone toward the improved management of natural resources. Stable isotope analysis of historical and modern samples spanning a century indicated that the niche width of an exploited fish community increased after the expansion of New Zealand fisheries. Since the 2000s most species increased their reliance on food webs supported by pelagic production, compared to coastal production supported by macroalgae, and shifted to a higher trophic level. Overall changes were coincident with ocean warming, climate oscillations, prey abundance and fishing intensity, but their effects were specific to each fish assemblage analyzed. Data derived from historical samples revealed how anthropogenic stressors can drive long-term shifts in the trophic structure of an exploited fish community. [ABSTRACT FROM AUTHOR]

Ecological interactions are found across ecosystems, facilitating comparison among systems with distinct species composition. The balance of positive and agonistic interactions among species may be sensitive to variation in the diversity and abundance of species in a community. We studied marine interaction networks among reef fishes on two oceanic islands characterized by high rates of endemism and restricted population connectivity: Rapa Nui (Easter Island) and Robinson Crusoe Island (Juan Fernandez Archipelago). Specifically, we examined whether the type and strength of behavioral interactions varied between these two isolated fish assemblages, how the relative proportions of agonistic and positive interactions compare, and which are the most important interacting species in each system. Combining detailed interaction records using standardized remote underwater video and visual censuses, we observed: (a) Rapa Nui contains 50% more fish species but half the fish densities than Robinson Crusoe, (b) despite these differences, the total number of interactions and proportion of all potentially interacting species were similar between the two oceanic islands; (c) the species that occupied the greatest proportion of all potential interactions in each community were endemic to their respective islands; (d) the relative frequency of positive and agonistic interactions varied, with more agonistic interactions in the more speciose reef system (Rapa Nui) and more positive interactions where fish densities were higher (Robinson Crusoe); and lastly (e) the relative abundance of each species predicted the interaction strength and the number of interactions across all reef fish species. It is of particular importance to understand the role of endemic species and processes affecting reef fish ecological networks on oceanic islands given the multiple anthropogenic threats to these isolated and vulnerable ecosystems. [ABSTRACT FROM AUTHOR]

The small-tooth flounder Pseudorhombus jenynsii (Paralichthyidae) is a common, yet relatively unstudied, flatfish occurring in estuaries and coastal waters around Australia. This study determined the age and growth of P. jenynsii using 1,228 specimens collected between 2004 and 2013 as bycatch by seine netting in estuaries and trawling in coastal waters in south-western Australia. Opaque zones in 1,043 sectioned otoliths were validated as forming annually by otolith edge analysis, with the first opaque zone becoming delineated after the first spring when fish are ~ 12 months old. Female P. jenynsii ranged in total length from 79 to 406 mm and males from 96 to 354 mm. The maximum observed age for females and males was 5 and 4 years, respectively. While the von Bertalanffy growth functions (VBGF) fitted to the lengths at age differed significantly between the sexes, this difference in the length at age was < 5% between the ages of 1 and 3 years (where most of the data lay). The VBGF parameters for both sexes combined are L∞: 381 mm, k: 0.53 year−1, t0: -0.15 years. The large variation in size-at-age of P. jenynsii is indicative of a presumed extended 5–6 months spring and summer spawning period. The presence of small (< 200 mm) and young (< 2 years old) P. jenynsii in estuaries and shallow coastal waters confirms the use of these environments as nursery habitats. [ABSTRACT FROM AUTHOR]

Seamounts and oceanic islands of the Chilean Exclusive Economic Zone at the intersection of the Nazca and Salas y Gómez ridges lie within one of the least explored areas in the world. The sparse information available, mainly for seamounts outside Chilean jurisdiction and shallow-water fauna of the Desventuradas Islands, suggests that the area is a hotspot of endemism. This apparent uniqueness of the fauna motivated the creation of the large Nazca-Desventuradas Marine Park (NDMP, ~ 300,000 km2) around the small islands San Felix and San Ambrosio in 2015. We report for the first time a detailed description of benthic microhabitats (i.e., centimeter to meter scale), macrohabitats (i.e., meter to kilometer-scale) and associated megafauna within the NDMP. Descriptions were based on analysis of fauna collected by trawling and ROV video observations from ~ 50 to 370 m depth. Rocky, coarse sand and silty sediment bottom habitats were observed at island slopes. In contrast, rocky and coarse sandy bottom habitats with a predominance of rhodoliths, thanatocoenosis, and other biogenic components were observed at seamounts. Mobile fauna and predators dominated the oceanic islands and nearby seamounts, whereas seamounts farther from the islands were dominated by sessile and hemisessile fauna that were mainly suspension and deposit feeders. Based on the register of 118 taxonomic units, our results provide an expanded and updated baseline for the benthic biodiversity of NDMP habitats, which seemed pristine, without evidence of trawling or anthropogenic debris. [ABSTRACT FROM AUTHOR]

Different groups parasitize the gills of fishes, and the organisms can interact in positive, negative, or neutral ways, depending on parasitic abundance, environmental conditions, and the availability of resources. Here, we studied the distribution of ectoparasites on the gills of the mullet Mugil curema in the Cabedelo port region (Brazil), asking if (1) the gill parasites of M. curema fix on specific host gill arches and/or (2) co-occur in the same gill arches within a host individual; (3) if the abundance of one parasite taxon affects the abundance of another on the same gill arches; and (4) considering distinct major groups, if parasites present patterns of co-occurrence on hosts and gill arches different from the expected at random. We used generalized linear models, generalized linear mixed models, and models with zero inflation to define the microhabitats (arches) with the highest abundances of parasites and null models to analyze the co-occurrences of gill parasite groups. Three taxa of Monogenea (Ligophorus brasiliensis Abdallah, Azevedo & Luque, 2009, Ligophorus sp. 1 and Ligophorus sp. 2) and six species of Copepoda were recorded (Bomolochus nitidus Wilson, 1911; Caligus praetextus Bere, 1936; Ergasilus atafonensis Amado & Rocha, 1997; Ergasilus bahiensis Amado & Rocha, 1997; Ergasilus caraguatatubensis Amado & Rocha, 1997 and Ergasilus lizae Krøyer, 1863). We found that, in general, the gill parasites were more abundant/prevalent on specific arches (I and II) of the hosts, shared such preferences and co-occurred on the gill arches. The presence of one taxon influenced the occurrence of another only in the arches I and II; as a result, the infracommunities were characterized as interactive in the gills of this host species. [ABSTRACT FROM AUTHOR]

Value of GIRT methodology for Underwater Cultural Heritage Management Another purpose of this fieldwork was to demonstrate the utility of GIRT and the GIRT survey methodology for informing underwater cultural heritage management. The Gathering Information via Recreational and Technical (GIRT) Scientific Divers citizen science program is a no-impact citizen science initiative that contends that regular systematic observations in the open sea environment can be used to note trends of stability and conditions and to inform science-based decision making in underwater cultural heritage management (Viduka [20], [21]). On November 26 and 28, 2019, three members of GIRT, supported by Paihia Dive staff, conducted the first archaeological condition observations of the ex-Greenpeace vessel I Rainbow Warrior I i (1987), located in the Cavalli Islands, New Zealand. Stemming from the GIRT monitoring of the I Rainbow Warrior i is a recognition of the condition of the vessel and the need to act quickly to better understand the corrosion rate and viability of in situ management options such as sacrificial anodes. [Extracted from the article]

Environmental DNA (eDNA) metabarcoding is a sensitive and widely used approach for species detection and biodiversity assessment. The most common eDNA collection method in aquatic systems is actively filtering water through a membrane, which is time consuming and requires specialized equipment. Ecological studies investigating species abundance or distribution often require more samples than can be practically collected with current filtration methods. Here we demonstrate how eDNA can be passively collected in both tropical and temperate marine systems by directly submerging filter membranes (positively charged nylon and non-charged cellulose ester) in the water column. Using a universal fish metabarcoding assay, we show that passive eDNA collection can detect fish as effectively as active eDNA filtration methods in temperate systems and can also provide similar estimates of total fish biodiversity. Furthermore, passive eDNA collection enables greater levels of biological sampling, which increases the range of ecological questions that eDNA metabarcoding can address. Bessey et al. present a method of passive eDNA collection from marine aquatic systems. This approach enables lower cost, high throughput sampling of aquatic environments and demonstrably collects high levels of eDNA for biodiversity studies. [ABSTRACT FROM AUTHOR]

The size and age at which individuals mature is rapidly changing due to plastic and evolved responses to fisheries harvest and global warming. Understanding the nature of these changes is essential because maturity schedules are critical in determining population demography and ultimately, the economic value and viability of fisheries. Detecting maturity changes is, however, practically difficult and costly. A recently proposed biphasic growth modelling likelihood profiling method offers great potential as it can statistically estimate age-at-maturity from population-level size-at-age data, using the change-point in growth that occurs at maturity. Yet, the performance of the method on typical marine fisheries datasets remains untested. Here, we assessed the suitability of 12 North Sea and Australian species' datasets for the likelihood profiling approach. The majority of the fisheries datasets were unsuitable as they had too small sample sizes or too large size-at-age variation. Further, datasets that did satisfy data requirements generally showed no correlation between empirical and model-derived maturity estimates. To understand why the biphasic approach had low performance we explored its sensitivity using simulated datasets. We found that method performance for marine fisheries datasets is likely to be low because of: (1) truncated age structures due to intensive fishing, (2) an under-representation of young individuals in datasets due to common fisheries-sampling protocols, and (3) large intrapopulation variability in growth curves. To improve our ability to detect maturation changes from population level size-at-age data we need to improve data collection protocols for fisheries monitoring. [ABSTRACT FROM AUTHOR]

Corynosoma australe and C. cetaceum are the most frequently reported acanthocephalans in fish from the Argentine Sea, particularly in central and northern areas. Their definitive hosts are otariids and odontocete cetaceans, respectively. The low specificity of these larvae, in combination with high infective capability and long survival periods in fish, make them potentially good biological markers for stocks and other biological features of their fish hosts. In order to determine the distribution patterns of these species and their determining factors, a large dataset composed by newly collected fish samples, published and unpublished data from previous studies by the authors in the region were analysed in relation to host and environmental variables. The complete dataset comprised a total of 5084 fish, belonging to 29 species distributed in 21 families and 9 orders. Host size and trophic habits arose as the main determinants of abundance for both species of Corynosoma, showing higher abundances on larger fish and on higher trophic levels, as it is usual for trophically transmitted parasites. Biogeographic province and depth (indirectly representing the temperature of water) were the main drivers of the spatial distribution, displaying a latitudinal pattern associated to the temperature clines created by the interaction of Malvinas and Brazil currents, determining a decrease in abundance southwards and towards the deeper areas. No patterns were found regarding the distribution of definitive hosts. The knowledge of these distribution patterns of Corynosoma spp. in fish at regional scale, as well as of their causes, provides useful information to design management and conservation policies thus contributing to maintain the full and sustainable productivity of fisheries. [ABSTRACT FROM AUTHOR]

A global analysis of the diet of chondrichthyes (23 species) was conducted during one bottom-trawl research cruise in the region where the highest catches of skates occurred off southwestern Atlantic. The diet was quantified by calculating the percentage frequency of occurrence of each prey. The influence of variables total length, sex, maturity stage, predator species, morphtype (sharks, skates, batoids), and depth on the diet was evaluated by fitting generalized linear models. The diet composition of chondrichthyes consisted mainly of crustaceans, polychaetes, and fish. The study region constituted a feeding ground for the majority of chondrichthyans species analyzed. The diet of chondrichthyes exhibited inter-specific differences sorted into three major trophic guilds and global ontogenetic shift. The consumption of crustaceans and polychaetes decreases with the total length of the chondrichthyes, whereas the consumption of fish increases as the predator grew in size. In addition, prey size of fish and crabs increased with increasing body size of predator, but large chondrichthyes also continued to feed on relatively small crabs. Trophic partitioning and ontogenetic diet shifts may act synergistically, favoring the coexistence of at least 23 species of chondrichthyes at all stages of their life histories, limiting the direct competition for food. [ABSTRACT FROM AUTHOR]

Selective pressures driving dispersal in vagile species often differ between males and females, resulting in sex-biased dispersal. Male-biased dispersal is common in mammals, where there is greater reproductive investment by females, and there is emerging evidence for a similar pattern in elasmobranchs. We examine the population structure of the short-tail stingray (Bathytoshia brevicaudata), a large, viviparous coastal species common in southern hemisphere waters. Using 11 nuclear (nDNA) microsatellite markers from 202 individuals in comparison to mitochondrial (mtDNA) data reported by Le Port and Lavery (J Hered 103:174–185, 2012), we elucidate patterns of dispersal at both southern hemisphere and New Zealand scales. At a global scale, estimates of population differentiation were comparable across marker types (microsatellite FST = 0.148, p < 0.001, mtDNA ϕST = 0.67, p < 0.001). In contrast, New Zealand structure was much weaker for microsatellite markers (FST = 0.0026, p > 0.05) than for mtDNA (ϕST = 0.054, p < 0.05). Female-only data displayed a greater degree of population differentiation from both nDNA and mtDNA compared to male-only data, and population assignment tests indicated that males were significantly more likely to be immigrants to the population from which they were sampled. We estimate that within New Zealand, male-mediated gene flow is at least fivefold greater than female-mediated gene flow. This molecular evidence for sex-biased dispersal in a batoid species adds further support to male-biased dispersal as a recurrent pattern in viviparous elasmobranchs. Many elasmobranch species are vulnerable to extinction, and understanding movement patterns is crucial to management of threatened populations. [ABSTRACT FROM AUTHOR]

The nematode Philometra pellucida (Jägerskiöld, 1893) (Philometridae) is redescribed from female specimens obtained from the abdominal cavity of the marine tetraodontiform fish (blackspotted puffer) Arothron nigropunctatus (Bloch & Schneider) (Tetraodontidae) off Lizard Island, Australia and off Okinawa, Japan. This is just the second record of this parasite since its description 125 years ago. Light and scanning electron microscopical examination of these nematodes revealed some taxonomically important, previously unreported morphological features, such as the number and arrangement of cephalic papillae, presence of the oesophageal cell nucleus and the size of first-stage larvae in the uterus. This new report of P. pellucida infecting A. nigropunctatus off Australia and Japan represents new host and geographical records. A key to the species of Philometra Costa, 1845 parasitising tetraodontiform fishes is provided. [ABSTRACT FROM AUTHOR]

Based on light and scanning electron microscopical studies, a new nematode parasite, Capillaria appendigera n. sp. (Capillariidae), is described from the intestine of the goldbanded jobfish Pristipomoides multidens (Day) (Perciformes, Lutjanidae) from the Arafura Sea West, off the northern coast of Australia. The new species, belonging to the subgenus Procapillaria Moravec, 1987, differs from other congeneric species from fishes mainly in the length (0.92-1.13 mm), shape and structure of the spicule, obtuse spines on the spicule sheath and the structure of eggs. It is characterised, in the male, by the presence of two well-developed dorsolateral caudal lobes, a pair of lateral papillae, a heavily sclerotised spicule with many rough transverse grooves covering almost the entice spicule surface (except for spicule ends), a spinose spicule sheath, and in the female, by a subterminal anus, mostly the presence of a large vulval appendage and by eggs (size 54-69 × 27-33 µm) encapsulated by a conspicuous light-coloured superficial layer. Capillaria appendigera n. sp. is the 12th nominal species of capillariids recorded from fishes in Australian waters and the second known capillariid species parasitising fishes of the perciform family Lutjanidae. In addition, four unidentifiable, morphologically different types of capillariid females, probably representing undescribed species, were recorded from the intestines of marine fishes off the northern coast of Australia: Capillariidae gen. sp. 1 and Capillariidae gen. sp. 2 from Lutjanus johnii (Bloch) and L. malabaricus (Bloch & Schneider), respectively (both Lutjanidae), Capillariidae gen. sp. 3 from Protonibea diacanthus (Lacépède) (Sciaenidae) and Capillariidae gen. sp. 4 from Rachycentron canadum (Linnaeus) (Rachycentridae). [ABSTRACT FROM AUTHOR]

A key aspect of equitable management of the world's fishery resources is the provision of traditional fishing access for Indigenous peoples. In Australia, increased recognition of the importance of fisheries to Indigenous culture and livelihoods over recent years has created a need for information on the species targeted to support policy and management. In the State of New South Wales (NSW), research on Indigenous fisheries catch composition is limited to two major studies. Here, we compare and combine data on Indigenous catch composition from these two studies to produce a comprehensive synthesis of current knowledge of Indigenous fisheries in NSW. The species harvested include more than 150 species of finfish and invertebrates, over 90 % of which are also harvested by commercial and recreational fishers. Our findings provide an empirical basis for future development of policy and management initiatives to meet the needs of Indigenous fishers and other stakeholders, as well as the principles of sustainable fisheries harvest. [ABSTRACT FROM AUTHOR]

The New Zealand fur seal ( Arctocephalus forsteri) is one of many pinniped species that has shown a remarkable recovery from the brink of extinction after cessation of commercial sealing during the eighteenth and nineteenth centuries. It is commonly believed that this species competes with recreational and commercial fisheries. We identified prey items using massive parallel sequencing from New Zealand fur seal faecal samples that were collected throughout the species distribution. The data support generalist feeding behaviour for this species. The diet composition showed significant geographical and inter-seasonal variation. As many as 46 species of fish and 18 species of cephalopod were identified from a single colony. The data suggest cartilaginous species (sharks, rays, and skates) constitute an important part of the New Zealand fur seal diet. Approximately 10 % of the species identified in the seal diet were of significant commercial value, which indicates some qualitative food competition between New Zealand fur seals and commercial fisheries in exploiting marine species. [ABSTRACT FROM AUTHOR]