Related Fish Species Research Articles

Competitive hierarchies among three species of juvenile coral reef fishes

Interspecific competition is often asymmetric, and it can limit the spatial distributions of competitively inferior species within a community. When asymmetric competition involves 2 or more component species, the ranking of species' competitive abilities may form competitive hier- archies (all species of higher rank out-compete all species of lower rank) or competitive networks (at least 1 species of lower rank out-competes ≥1 species of higher rank). Expectations of resource monopolization and patterns of distribution and abundance among species in competitive net- works are expected to differ from those in competitive hierarchies. We conducted a field experi- ment to evaluate the relative competitive abilities of juveniles of 3 closely related species of reef fish (bird wrasse Gomphosus varius, fivestripe wrasse Thalassoma quinquevittatum and the sixbar wrasse T. hardwicke) on Moorea, French Polynesia. We controlled for intrinsic variation in sur- vivorship among species and found that competition among these 3 species was highly asymmet- ric, resulting in a simple competitive hierarchy (sequence of competitive ability from superior to inferior competitors): fivestripe wrasse > bird wrasse > sixbar wrasse. We surveyed densities of the 3 reef fish species on 55 patch reefs and observed significant negative spatial covariation between superior and inferior competitors, consistent with competitive hierarchies that limit the spatial dis- tributions of the inferior species (sixbar wrasse). Our work demonstrates that intense asymmetric competition and the formation of competitive hierarchies may be an important determinant of resource monopolization and patterns of distribution and abundance in reef fishes.

The Determination of Some Heavy Metals and Minerals in the Tissues and Organs of the Capoeta umbla Fish Species in Relation to Body Size, Sex, and Age

In this study, the levels of iron, copper, zinc, (manganese), cobalt, cadmium, lead, chrome, arsenic, mercury, nickel, calcium, and magnesium in the muscle, gill, skin, liver, gonad, and kidney of Capoeta umbla caught from Lake Hazar, Elazig, Turkey were investigated. The concentrations of detected heavy metals were the highest in the liver and the lowest in the muscle. In addition, it has been found that the concentrations of heavy metals and minerals were found to be different in various tissues and organs. The amounts of heavy metals showed differences according to the weight, length, sex, and age groups of the fish. The results were discussed and compared with tolerable values for heavy metals provided by the EPA, WHO, FAO, and Turkish Food Codex to determine whether this species has any risk for human consumption. Bu calismada, Hazar Golu'nden (Elazig, Turkiye) yakalanan Capoeta umbla'nin kas, solungac, deri, karaciger, gonad ve bobrek dokusundaki demir, bakir, cinko, mangan, kobalt, kadmiyum, kursun, krom, arsenik, civa, nikel, kalsiyum ve magnezyum duzeyleri incelenmistir. Tespit edilen agir metal ve minerallerin en yuksek duzeyleri karaciger en dusuk duzeyleri ise kas dokusunda tespit edilmistir. Ayrica bu agir metallerin konsantrasyonlari farkli doku ve organlarda farkli bulunmustur. Agir metal birikimlerinin baligin yas gruplarina, vucut agirligina, uzunluguna ve cinsiyetine bagli olarak degisiklik gosterdigi saptanmistir. Bu turun insanlar tarafindan tuketilmesinin herhangi bir risk tasiyip tasimadigi EPA, WHO, FAO ve Turk Gida Kodeksi tarafindan onerilen kabul edilebilir degerler ile karsilastirilarak tartisilmistir. Anahtar Kelimeler: Agir metal, birikim, Capoeta umbla, Hazar Golu, mineral.

Comunidades de parásitos eumetazoos de peces labrisómidos de Chile central

This study compares the parasite communities of 4 phylogenetically related fish species that belong to the family Labrisomidae; Auchenionchus microcirrhis, A. variolosus, A. crinitus and Calliclinus geniguttatus. These fish are sympatric in the intertidal zone of central Chile (33°S), from where 182 specimens were collected. Twenty-one parasite taxa were found within the 4 sampled fish species. Three parasite species were the most common in the labrisomid fish: an undetermined leech (Piscicolidae), the copepod Holobomolochus chilensis, and the digenean Helicometrina nimia. Most of the parasites were host generalists. C. geniguttatus had a low similarity of parasite composition respect to Auchenionchus spp. The variation in parasite communities among labrisomid species were related to fish length and possibly to environmental variables.

Analysis of mitochondrial DNA in Adriatic sardine (<i>Sardina pilchardus</i>): a preliminary study

To determine the phylogenetic history of sardines researchers use mitochondrial DNA (mtDNA). Mitochondrial DNA contains highly informative polymorphic sites. The cytochrome b (cyt b) gene has been especially used by investigators because of its sufficient point mutation rate, enabling discrimination of closely related fish species, and determination of interspecific variability in pelagic fish species for population identification. Scientific surveys based on meristic, morphometric, and reproductive data suggested that two subpopulations of sardines coexisted in the Northern-Middle Adriatic Sea. Mitochondrial DNA analysis of sardines from the Adriatic Sea has never been conducted in the Republic of Croatia. This study included 14 sardine samples from three separate locations, as well as 30 different haplotype sequences retrieved from GenBank. The aim of this study was to determine the number of haplotypes in sardine populations from the Adriatic Sea, as well as to determine differences between populations. Mitochondrial DNA sequence analysis revealed 11 different haplotypes of sardines from the Adriatic Sea. The differences between samples from different locations were not scientifically significant, and the results of this study indicate homogeneity in the Adriatic sardine stock. However, three parsimony informative mutations found in our samples produce a clearly visible distinction between the Adriatic sardine samples and samples obtained from the seas adjacent to the Adriatic. This distinction of the Adriatic sardine samples can have applications in fisheries and fishery product quality testing.

Speciation leads to divergent methylmercury accumulation in sympatric whitefish

Central European lake whitefish (Coregonus spp.) colonized Swiss lakes following the last glacial retreat and have undergone rapid speciation and adaptive radiation. Up to six species have been shown to coexist in some lakes, and individual species occupy specific ecological niches and have distinct feeding and reproductive ecologies. We studied methylmercury (MeHg) accumulation in sympatric whitefish species from seven Swiss lakes to determine if ecological divergence has led to different rates of MeHg bioaccumulation. In four of seven lakes, sympatric species had distinctly different MeHg levels, which varied by up to a factor of two between species. Generally, species with greater MeHg levels were smaller in body size and planktivorous, and species with lower MeHg were larger and benthivorous. While modest disparities in trophic position between species might be expected a priori to explain the divergence in MeHg, δ15N of bulk tissue did not correlate with fish MeHg in five of seven lakes. Results of a nested ANCOVA analysis across all lakes indicated that only two factors (species, lake) explained substantial portions of the variance, with species accounting for more variance (52 %) than inter-lake differences (32 %). We suggest that differences in MeHg accumulation were likely caused by diverging metabolic traits between species, such as differences in energy partitioning between anabolism and catabolism, potentially interacting with species-specific prey resource utilization. These results indicate substantial variability in MeHg accumulation between closely related fish species, illustrating that ecological speciation in fish can lead to divergent MeHg accumulation patterns.

Evaluating ontogenetic patterns of habitat use by reef fish in relation to the effectiveness of marine protected areas in West Hawaii

Identifying habitats important to vulnerable life stages of reef fish is an important goal for the effective design and management of Marine Protected Areas (MPAs). However, data on habitat requirements for most fish species are limited. Using a benthic habitat map that characterized reef habitats on the island of Hawaii , we examined ontogenetic patterns of habitat use by each of the life stages of endemic (i.e., Ctenochaetus strigosus; Ctenochaetus hawaiiensis), non-targeted species (i.e., Acanthurus nigrofuscus; Chromis agilis; Thallasoma duperrey; Paracirrhites arcatus) and targeted aquarium fish species (Zebrasoma flavescens; C. strigosus; C. hawaiiensis; Chaetodon multicinctus) in relation to the effectiveness of existing MPAs designed to replenish aquarium fishes targeted by the aquarium trade. Our study empirically demonstrates that many species shift habitats ontogenetically while others remained in the same habitats as they matured. And among those that shifted habitats, depending on species, adults shifted either to more structured (branching coral in mid-depth aggregate and boulder habitats in 5 to 11m depths) or to less structured substrates (shallow turf-rich boulder habitats in 0 to 11m depths). In addition, this study shows how the spatial characteristics of the MPA (i.e., reef size) may be important to reef fish assemblages and ultimately the effectiveness of MPAs to replenish protected ornamental fishes. It is therefore critically important that the management and future design of MPAs provide sufficient diversity and quantities of habitats for all life stages of managed species in order to ensure the replenishment necessary to satisfy their conservation needs and management goals.

Biological Characteristics of Fish Germ Cells and their Application to Developmental Biotechnology

We have revealed several unique characteristics of germ cell development using rainbow trout, including the fact that spermatogonia transplanted into the peritoneal cavity of newly hatched embryos migrate toward recipient gonads, that spermatogonia transplanted into female recipients start oogenesis and produce functional eggs and that diploid germ cells transplanted into triploid trout can complete gametogenesis. By combining these unique features of fish germ cells, we established allogeneic and xenogeneic transplantation systems for spermatogonia in several fish species. Spermatogonia isolated from the mature testes of vasa-green fluorescent protein (Gfp) transgenic rainbow trout were transplanted into the peritoneal cavity of triploid masu salmon newly hatched embryos. These spermatogonia migrated toward recipient salmon genital ridges with extending pseudopodia and were subsequently incorporated into them. We further confirmed that the donor-derived spermatogonia resumed gametogenesis and produced sperm and eggs in male and female salmon recipients, respectively. By inseminating the resulting eggs and sperm, we obtained only rainbow trout offspring in the F1 generation, suggesting that the triploid salmon recipients produced functional gametes derived only from donor trout. We further confirmed that this intra-peritoneal transplantation of germ cells is applicable to several marine fishes, which could be of benefit in the production of bluefin tuna that has a large broodstock (>100 kg) and is difficult to maintain in captivity. Gamete production of bluefin tuna could be more easily achieved by generating a surrogate species, such as mackerel, that can produce tuna gametes.

Physiological and genetic basis for variation in migratory behavior in the three-spined stickleback, Gasterosteus aculeatus

AbstractClosely related species of fish often exhibit different migration patterns. Even within species, anadromous and resident populations can be found in a diverse number of taxa. Although several environmental factors that regulate behavioral and physiological changes associated with fish migration have been identified, the genetic mechanisms underlying the variation in the ability to respond to these environmental cues in fishes that show different migratory behaviors are not well known. The three-spined sticklebackGasterosteus aculeatus(Linnaeus 1758) is a good model system for elucidation of the genetic basis for variation in migratory behaviors and other physiological changes associated with migration. First, the three-spined stickleback exhibits great inter-population variation in migration patterns. Second, genetic and genomic tools are now available for studying this species. In the present study, variation in the migration patterns amongG. aculeatuspopulations and the recent progress in our understanding of the genetic and physiological basis for variation in traits important forG. aculeatusmigration are reviewed.

A microinjection protocol for the generation of transgenic killifish (Species: Nothobranchius furzeri)

A challenge in age research is the absence of short-lived vertebrate model organisms. The turquoise killifish Nothobranchius furzeri has an exceptionally short lifespan of 4-10 months depending on the strain. Thus, it possesses the shortest known maximum lifespan of a vertebrate species that can be bred in captivity. Here we show the successful introduction of DNA and RNA molecules into the one-cell embryo of N. furzeri. For this purpose, we adapted existing microinjection protocols to inject through the remarkably thick and robust chorion of N. furzeri's eggs. The injected DNA transgene was integrated into the genome and transmitted to subsequent generations as indicated by the expression of the fluorophore enhanced green fluorescent protein (EGFP). Furthermore, we could confirm a special phase during embryonic development in which embryogenesis occurs within a re-aggregated mass of previously dispersed cells as it has been described for other related cyprinodont fish species. The transgenesis protocol described here provides a basis for a variety of genetic manipulations including overexpression of genes and determining their effects on lifespan and longevity. The feasibility to perform transgenesis is an important step to establish N. furzeri as a new model in age research.

Conflicting effects of woody debris on stream fish populations: implications for management

Summary1. Coarse woody debris (CWD) in stream channels causes changes in flow, sedimentation and ratios of pool to riffle areas. There is a consensus among fishery managers and scientists that CWD is beneficial to stream fish communities because of its enhancement of habitat diversity, invertebrate production and cover. Our hypothesis was that CWD accumulation or introduction would not increase in‐stream habitat capacity for all species and their ontogenic stages at reach and stream scales.2. The study used a system of gravel‐bed streams with naturally dynamic CWD accumulations and a fish community consisting of Salmo trutta, Cotttus gobio, Phoxinus phoxinus, Lampetra cf planeri, Nemacheilus barbatulus and Anguilla anguilla. Cotttus gobio and L. cf planeri are protected by an EU Directive and S. trutta is exploited for angling. Riffles, pools and CWD matrices, considered as the basic habitat/spatial units of channel structure, were sampled separately and abundance of each fish species quantified seasonally at each spatial scale.3. Multiple‐pass electric fishing techniques were used. Capture efficiencies were calculated for species, habitat and season. Areal densities (number m−2) were compared for habitat types and season using nonparametric anova. Canonical analysis and stepwise multiple regression were used to show the most influential physical variables on fish density. Densities were also compared by unit volume (numbers m−3) for pools and CWD matrices to investigate direct three‐dimensional use for cover. Reach‐scale densities for each fish species in relation to habitat composition were made using Spearman rank correlation of habitat‐scale densities with proportionate areas of the different habitat units in the reach.4. Habitat‐scale densities of bullheads and age 0+ trout were negatively correlated with depth and CWD areas for some seasons. Densities of lampreys, older trout, eels and minnows were positively correlated with depth in some seasons. Water depth had the most consistent influence on fish abundance at the habitat unit scale. Three‐dimensional comparisons of pools and CWD matrices indicated that only trout older than 1+ may use CWD habitats as cover.5. Reach‐scale densities of 0+ trout and bullheads were significantly correlated with proportion of riffle area and negatively with CWD and combined CWD‐pool habitat area in the reach. Densities of older trout, large eels and lampreys were positively correlated with CWD area and combined CWD‐pool area in some seasons. Inundation of riffles caused by impoundment upstream of CWD accumulations reduced spawning habitat for trout, bullheads, brook lampreys, minnows and stone loach. A trade‐off was an increase in refugia for older trout, minnows and eels.6. Coarse woody debris accumulation in streams is not beneficial to all species or ontogenic stages in a mixed species population and could severely limit essential habitat areas for some species. Thus, physical manipulation of channels should be implemented only after a thorough study of the habitat relationships of all species present, especially where protected species coexist with target species. The relative importance of in‐stream morphological changes depends on the spatial and temporal scale of the species life histories.

Heavy metal (Cd, Cr, Cu, Hg, Pb, Zn) concentrations in seven fish species in relation to fish size and location along the Yangtze River

The objective of this paper is to assess the regulation of the accumulation of heavy metals in the aquatic environment and different fish species. Water and fish samples were collected from upper to lower reaches of the Yangtze River. The heavy metal (Cd, Cr, Cu, Hg, Pb, Zn) concentrations in the muscle tissue of seven fishes were measured. Additionally, the relationships between heavy metal concentrations in fish tissue and fish size (length and weight), condition factor, water layer distribution, and trophic level were investigated. Metal concentrations (milligrams per kilogram wet weight) were found to be distributed differently among different fish species. The highest concentrations of Cu (1.22mg/kg) and Zn (7.55mg/kg) were measured in Pelteobagrus fulvidraco, the highest concentrations of Cd (0.115mg/kg) and Hg (0.0304mg/kg) were measured in Silurus asotus, and the highest concentrations of Pb (0.811mg/kg) and Cr (0.239mg/kg) were measured in Carassius auratus and Cyprinus carpio. A positive relationship was found between fish size and metal level in most cases. The variance of the relationships may be the result of differences in habitat, swimming behavior, and metabolic activity. In this study, fishes living in the lower water layer and river bottom had higher metals concentrations than in upper and middle layers. Benthic carnivorous and euryphagous fish had higher metals concentrations than phytoplankton and herbivorous fish. Generally, fish caught from the lower reach had higher metals concentrations than those from the upper reach. Cadmium and lead concentrations in several fishes exceeded the permissible food consumption limits, this should be considered to be an important warning signal.

A Landscape‐Based Classification of Fish Assemblages in Sampled and Unsampled Lakes

AbstractWe related fish species patterns and landscape‐scale environmental data from 216 Michigan lakes to identify repeatable types of fish assemblages, identify environmental factors related to assemblage types, and classify fish assemblages in unsampled lakes. Multivariate regression tree modeling of fish species abundances identified six assemblage types that were explained by degree‐days during the ice‐free period, lake surface area, and mean lake surface temperature. Warmwater species dominated southern lakes, while coolwater and coldwater species had higher abundances in northern lakes. Coolwater species were present in large southern lakes, whereas warmwater species were excluded from northern lakes that had low mean surface temperatures or low degree‐days. These results suggest that patterns of lake fish assemblages are shaped by differences in climate as well as lake‐specific differences in surface temperature regimes and in vertical availability of coldwater and coolwater habitats. Because we related fish patterns to readily available landscape‐level data, our approach can be used to characterize fish assemblages in all lakes across broad geographic extents.

Exclusive Sensitization to Striped Catfish (Pangasianodon hypophthalmus) and Closely Related Fish Species

Fish allergy usually implies cross-sensitization to numerous species due to high sequence homology between different fish parvalbumins, the major fish allergen. We report about a 36-year old female patient who developed anaphylaxis after eating striped catfish while other fish were tolerated.

Divergent hormonal responses to social competition in closely related species of haplochromine cichlid fish

The diverse cichlid species flocks of the East African lakes provide a classical example of adaptive radiation. Territorial aggression is thought to influence the evolution of phenotypic diversity in this system. Most vertebrates mount hormonal (androgen, glucocorticoid) responses to a territorial challenge. These hormones, in turn, influence behavior and multiple aspects of physiology and morphology. Examining variation in competition-induced hormone secretion patterns is thus fundamental to an understanding of the mechanisms of phenotypic diversification. We test here the hypothesis that diversification in male aggression has been accompanied by differentiation in steroid hormone levels. We studied two pairs of sibling species from Lake Victoria belonging to the genera Pundamilia and Mbipia. The two genera are ecologically differentiated, while sibling species pairs differ mainly in male color patterns. We found that aggression directed toward conspecific males varied between species and across genera: Pundamilia nyererei males were more aggressive than Pundamilia pundamilia males, and Mbipia mbipi males were more aggressive than Mbipia lutea males. Males of both genera exhibited comparable attack rates during acute exposure to a novel conspecific intruder, while Mbipia males were more aggressive than Pundamilia males during continuous exposure to a conspecific rival, consistent with the genus difference in feeding ecology. Variation in aggressiveness between genera, but not between sibling species, was reflected in androgen levels. We further found that M. mbipi displayed lower levels of cortisol than M. lutea. Our results suggest that concerted divergence in hormones and behavior might play an important role in the rapid speciation of cichlid fishes.

SCALES OF VARIABILITY IN FIN RAY COUNTS OF FLOUNDER, PLATICHTHYS FLESUS L. ON IRISH AND WELSH COASTS

Meristic variation within a fish species can arise due to environmental factors and can aid investigation between fish stocks and closely related juvenile fish species. The aim of this study was to investigate the spatial variation in meristic characteristics for juvenile flounder Platichthys flesus from Irish and Welsh coasts. Five meristic fin ray counts were taken from 120 fish from nursery grounds in three regions (west Irish coast, east Irish coast and Welsh coast). Statistical analysis revealed regional variability for two of the meristic counts (dorsal and anal fin rays). A discriminant function analysis revealed a weak separation of the three regions. This separation improved when samples from the east Irish region were eliminated, with 65% of the fish from the Irish west coast and 73% of the fish from Wales correctly classified.

Ecological connectivity and niche differentiation between two closely related fish species in the mangrove-seagrass-coral reef continuum

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 477:201-215 (2013) - DOI: https://doi.org/10.3354/meps10171 Ecological connectivity and niche differentiation between two closely related fish species in the mangrove-seagrass-coral reef continuum Charlotte Berkström*, Tove L. Jörgensen, Micaela Hellström Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden *Email: charlotte.berkstrom@su.se ABSTRACT: We aim to understand ontogenetic shifts in habitat use and feeding patterns by 2 fish species, Lutjanus fulviflamma and L. ehrenbergii, within a tropical seascape in East Africa. Stomach contents and stable isotope signatures of muscle tissues (δ13C and δ15N) were compared between and within species. Fish of all life stages and potential food items were sampled from mangrove creeks, seagrass beds, and coral reefs around Mafia Island, Tanzania. Due to similarities in morphology between species, correct species identity was confirmed using genetic barcoding (mtDNA, partial sequence of cytochrome oxidase subunit I [COI]). Stable isotope analysis in R (based on mixing models) confirmed that δ13C and δ15N values in L. fulviflamma and L. ehrenbergii reflected those of prey items caught in different habitats. Diets and mean δ13C and δ15N values of muscle tissue differed between life stages of fish, indicating ontogenetic changes in habitat and diet. L. fulviflamma and L. ehrenbergii differed in diet and δ13C and δ15N values of muscle tissue, although they overlapped in habitat use, suggesting food resource partitioning between the 2 species. Furthermore, diet overlap indexes were low between subadult species in mangrove and seagrass or coral habitats. L. fulviflamma displayed a diet shift with decreasing importance of small crustaceans in juveniles and an increasing importance of prey fishes in subadults and adults. L. ehrenbergii showed the opposite pattern. The study verifies feeding interlinkage within the mangrove-seagrass-coral reef continuum in Mafia Island by providing strong evidence of ontogenetic migration. Understanding these connections will enhance our ability to manage tropical seascapes, and highlights the need to include multiple habitats in marine protected areas. KEY WORDS: Stable isotopes · Stomach content · Ontogenetic shifts · Connectivity · Resource partitioning · Coral reef · Seagrass · Mangrove Full text in pdf format PreviousNextCite this article as: Berkström C, Jörgensen TL, Hellström M (2013) Ecological connectivity and niche differentiation between two closely related fish species in the mangrove-seagrass-coral reef continuum. Mar Ecol Prog Ser 477:201-215. https://doi.org/10.3354/meps10171 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 477. Online publication date: March 12, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Haematology and plasma chemistry of the red top ice blue mbuna cichlid (Metriaclima greshakei)

Clinical haematology and blood plasma chemistry can be used as a valuable tool to provide substantial diagnostic information for fish. A wide range of parameters can be used to assess nutritional status, digestive function, disease identification, routine metabolic levels, general physiological status and even the assessment and management of wild fish populations. However to evaluate such data accurately, baseline reference intervals for each measurable parameter must be established for the species of fish in question. Baseline data for ornamental fish species are limited, as research is more commonly conducted using commercially cultured fish. Blood samples were collected from sixteen red top ice blue cichlids (Metriaclima greshakei), an ornamental freshwater fish, to describe a range of haematology and plasma chemistry parameters. Since this cichlid is fairly large in comparison with most tropical ornamental fish, two independent blood samples were taken to assess a large range of parameters. No significant differences were noted between sample periods for any parameter. Values obtained for a large number of parameters were similar to those established for other closely related fish species such as tilapia (Oreochromis spp.). In addition to reporting the first set of blood values for M. Greshakei, to our knowledge, this study highlights the possibility of using previously established data for cultured cichlid species in studies with ornamental cichlid fish.

Development of an Optimized Protein Chip for the Detection of Fish Parvalbumin Allergen

Food allergy has become a serious human health concern. With more than 160 kinds of food allergens have been identified to date, allergen detection has become challenging. Most current allergen detection methods are capable of detecting only a few allergens at a time. The objective of this work was to develop a sensitive method for the detection of fish parvalbumin in food matrices employing a 3D aldehyde protein chip, which has the capacity to detect several allergens simultaneously. Upon testing, the protein chip was found to be highly specific in allergen detection but was found to cross-react to some extent with the allergens from some closely related fish species. The allergen recoveries ranged from 72.1% to 95.2%. The inter- and intra- assay coefficients of variation were < 18% and < 12% respectively. The LOD (limit of detection) and LOQ (limit of quantitation) of the protein chip of 0.048 and 0.087 mg parvalbumin/kg food, respectively, was sensitive enough given the threshold limit for the fish allergen. The newly developed assay seems reliable enough in detecting fish parvalbumin from various foods, food products and thus could prove useful in detecting and minimizing the instances of fish allergy. Keywords: Allergen, Protein chip, Fish, Parvalbumin, Detection, Food allergy, 3D aldehyde protein chip, Limit of quantitation, Limit of detection, Threshold limit

The seasonal and spatial patterns of ingestion of polyfilament nylon fragments by estuarine drums (Sciaenidae)

Artisanal fisheries in tropical estuaries are an important economic activity worldwide. However, gear (e.g. ropes, nets, buoys, crates) and vessels are often in use under dangerous conditions. Polyfilament nylon ropes are used until they are well beyond human and environmental safety limits. Severe wear and tear results in the contamination of the environment with micro-fragments. The spread of these fragments in the marine environment and their ingestion by the biota are documented in the scientific literature and are increasing concerns. The aim of this study was to evaluate the ingestion of plastic fragments by two fish (drum) species in relation to seasonal, habitat and fish size-class variation. The stomach contents of 569 individuals of Stellifer brasiliensis and Stellifer stellifer from the main channel of the Goiana Estuary were examined to identify variation in the number and the weight of plastic fragments and relate this variation to differences among the seasons (early dry, late dry, early rainy and late rainy), the habitats within the estuary (upper, middle and lower) and the size classes of the fish (juveniles, sub-adults and adults). Plastic fragments were found in 7.9% of the individuals of these two drum species captured from December 2005 to August 2008. Nylon fragments occurred in 9.2% of S. stellifer and 6.9% of S. brasiliensis stomachs. The highest number of nylon fragments ingested was observed in adults during the late rainy season in the middle estuary. Blue polyfilament nylon ropes are used extensively in fisheries and can be lost, inappropriately discarded or damaged during use in the estuary. These fragments were the only type of plastic detected during this study. The ingestion of nylon fragments by fish probably occurred during the animals' normal feeding activities. During the rainy season, the discharge of freshwater transports nylon fragments to the main channel and makes the fragments more available to fish. Fishery activities are responsible for a significant amount of the marine debris found in the estuary. The ingestion of fragments of nylon threads by fish is a demonstrated form of pollution in the Goiana Estuary. The physiological and toxicological consequences of the ingestion of this type of debris are unknown, as is the actual extent of the problem worldwide. The solutions to the problem are in the hands of authorities and communities alike because the good care and timely replacement of gear requires education, investment and effective policies.

Morphological patterns of five fish species (four characiforms, one perciform) in relation to feeding habits in a tropical reservoir in south-eastern Brazil

Morphological patterns of five fish species (four characiforms, one perciform) in relation to feeding habits in a tropical reservoir in south-eastern Brazil