Sparid Species Research Articles

Link between bacterial communities and contrasted loads in ectoparasitic monogeneans from the external mucus of two wild sparid species (Teleostei)

BackgroundWhile teleost fishes represent two thirds of marine vertebrates, the role of their external microbiota in relationship with their environment remains poorly studied, especially in wild populations. Hence, the interaction of their microbiota with ectoparasites is largely unknown. Microbiota can act as a protective barrier against pathogens, and/or be involved in host recognition by parasites. Thus, host-parasite associations should now be considered as a tripartite interplay where the microbiota shapes the host phenotype and its relation to parasites. Monogeneans (Platyhelminthes) are direct life cycle ectoparasites commonly found on teleost skin and gills. The role of bacterial communities within skin and gill mucus which either pre-exist monogeneans infestation or follow it remain unclear. This is investigated in this study using the association between Sparidae (Teleostei) and their specific monogenean ectoparasites of the Lamellodiscus genus. We are exploring specificity mechanisms through the characterization of the external mucus microbiota of two wild sparid species using 16s rRNA amplicon sequencing. We investigated how these bacterial communities are related to constrated Lamellodiscus monogeneans parasitic load.ResultsOur results revealed that the increase in Lamellodiscus load is linked to an increase in bacterial diversity in the skin mucus of D. annularis specimens. The date of capture of D. annularis individuals appears to influence the Lamellodiscus load. Correlations between the abundance of bacterial taxa and Lamellodiscus load were found in gill mucus of both species. Abundance of Flavobacteriaceae family was strongly correlated with the Lamellodiscus load in gill mucus of both species, as well as the potentially pathogenic bacterial genus Tenacibaculum in D. annularis gill mucus. Negative correlations were observed between Lamellodiscus load and the abundance in Vibrionaceae in gill mucus of D. annularis, and the abundance in Fusobacteria in gill mucus of P. acarne specimens, suggesting potential applications of these bacteria in mitigating parasitic infections in fish.ConclusionsOur findings highlight the dynamic nature of fish microbiota, in particular in relation with monogeneans infestations in two wild sparid species. More generally, this study emphasizes the links between hosts, bacterial communities and parasites, spanning from the dynamics of co-infection to the potential protective role of the host’s microbiota.

Identification of Sparidae species based on COI and 16S rRNA DNA barcoding along the coast of Oman

Fish species belonging to the Sparidae family hold significant commercial value for Oman’s fisheries. Although 18 out of 132 known sparid species have been reported in Omani waters, accurate morphological identification remains challenging for many species. We used DNA barcoding based on cytochrome oxidase subunit І (COI) and 16S ribosomal RNA (16S rRNA) to identify commercially important sparid species. Sixty-three specimens were collected from three major Omani fisheries landings, namely Khasab, Suhar, and Salalah, spanning over 3165 km of coastline. Sequences of 16 S rRNA (521 bp) and COI (506 bp) identified 16 species by 16S rRNA, ten species by COI. Notably, Dentex gibbosus was reported for the first time in Omani waters. The identified 16 species, phylogenetically, belong to two genetically distinct groups. The interspecific genetic distances among species ranged from 0.011 to 0.279 based on 16S rRNA and 0.104–0.259 based on COI, indicating different groups within Omani waters. DNA barcoding provided high taxonomic resolution of sparid biodiversity in Oman and the surrounding region. Additionally, the study contributes to establishing a reference database for the Sparidae family of species from Oman.

Phylogenetic Relationships and Genetic Diversity of Some Sparid Species from The Egyptian Mediterranean Sea Using 16S rRNA Gene

Phylogenetic Relationships and Genetic Diversity of Some Sparid Species from The Egyptian Mediterranean Sea Using 16S rRNA Gene

Sparid species discrimination by COIBar-RFLP in commercial products

Processed seafood products are subject to fraudulent species substitution practices that pose problems not only economically but also for human health due to the risk of allergies. DNA-based molecular techniques offer an undoubted contribution to unraveling commercial fraud in processed seafood products, and several investigations have been conducted to develop specific and rapid assays for the identification of fish species. In this context, we hypothesize that the Cytochrome Oxidase I (COI) Barcode-Restriction Fragment Length Polymorphisms (COIBar- RFLP) strategy may be a useful molecular tool to quickly assess the authenticity of seafood products because (i) it takes advantage of the specific discriminatory power of the COI gene as a barcode and of the robust Restriction Fragment Length Polymorphism methodology and (ii) the interspecific variation in the digestion pattern obtained using the restriction enzymes allows bypassing the gene sequencing step. The Sparidae family includes species of high commercial value and many sparid species are difficult to recognize considering only their morphological features; thus, misidentifications are frequent. The aim of this work was to identify sparid species in processed products using the COIBar-RFLP strategy with the MspI restriction enzyme which yielded differential digestion patterns and unveiled two cases of species substitution. The proposed methodology could be used in food control laboratories to combat the widespread habit of fraudulent species substitution in the fishing industry.

Host-microbiota-parasite interactions in two wild sparid fish species, Diplodus annularis and Oblada melanura (Teleostei, Sparidae) over a year: a pilot study

BackgroundThe microbiota in fish external mucus is mainly known for having a role in homeostasis and protection against pathogens, but recent evidence suggests it is also involved in the host-specificity of some ectoparasites. In this study, we investigated the influence of seasonality and environmental factors on both fish external microbiota and monogenean gill ectoparasites abundance and diversity and assessed the level of covariations between monogenean and bacterial communities across seasons. To do so, we assessed skin and gill microbiota of two sparid species, Oblada melanura and Diplodus annularis, over a year and collected their specific monogenean ectoparasites belonging to the Lamellodiscus genus.ResultsOur results revealed that diversity and structure of skin and gill mucus microbiota were strongly affected by seasonality, mainly by the variations of temperature, with specific fish-associated bacterial taxa for each season. The diversity and abundance of parasites were also influenced by seasonality, with the abundance of some Lamellodiscus species significantly correlated to temperature. Numerous positive and negative correlations between the abundance of given bacterial genera and Lamellodiscus species were observed throughout the year, suggesting their differential interaction across seasons.ConclusionsThe present study is one of the first to demonstrate the influence of seasonality and related abiotic factors on fish external microbiota over a year. We further identified potential interactions between gill microbiota and parasite occurrence in wild fish populations, improving current knowledge and understanding of the establishment of host-specificity.

Mitochondrial Analysis of Sparidae Species to Detect a New DNA Barcoding Marker for Dentex gibbosus to Utilize against Fraud.

Dentex gibbosus (Pink dentex) is a fish species of increasing economic interest in the Mediterranean Sea that is consumed both whole and processed. The growing value of this sparid in European markets is responsible for its substitution with fraudulent species. The distinctive morphologic feature of D. gibbosus is the conspicuous hump on the forehead in the older and larger specimens. However, the head is regularly convex in young individuals, requiring high skills and competencies for correct identification. Authentication becomes even more challenging in the case of prepared and processed products. Therefore, the molecular characterization of Pink dentex plays a crucial role in preventing commercial fraud with species substitution. This paper proposes a comparative mitogenome analysis between 19 sparid species of commercial interest as a tool to accurately design species-specific primers targeting a fragment of the NAD2 gene for the identification of D. gibbosus. We successfully detected Pink dentex DNA both using endpoint and real-time PCR. The findings showed the high specificity of the designed primers, demonstrating this a suitable, fast, and cost-effective method that could be used for the unambiguous identification of Pink dentex. This innovative approach for sparid authentication is expected to contribute to seafood traceability, public health assurance, integrity, and the credibility of the seafood industry.

Evaluation of the inland fisheries in Basrah Province during 2020-2021, Iraq

The purpose of the study was to provide up-to-date information on inland fisheries landings in Basrah province, Iraq. During 2020-2021, the species composition, species and total landings, and trends at six landing locations in the research region were assessed. There were seven species of cyprinids, three species of cichlids, three species of mullet, and two species of sparids and silurids. The foreign species C. carpio, tilapias species, and C. auratus dominated landings, accounting for 44.2% of the entire catch. In contrast, the highly prized native species (M. sharpeyi, L. xanthopterus, C. luteus, and A. grypus) accounted for just 12.4%. In 2020 and 2021, the total landings reached 2,427.78 t and 2,365.15 t, respectively, greater than the previous years since 2009. This is attributable to the frequency of alien species and the rise in fishing effort, as measured by the number of fishermen and fishing vessels. Improving inland fisheries requires enhancing the stocks of native species, minimizing the dissemination and impacts of some exotic species, and activating national regulations governing fishing, exploitation, and conservation of aquatic life from the fisheries management perspective.

Life-history styles of eight morphologically similar estuary-associated sparid species from southern Africa

Life-history styles of eight morphologically similar estuary-associated sparid species from southern Africa

The role of macroalgae as nursery areas for fish species within coastal seascapes

Abstract One of the most critical ecosystem functions provided by shallow coastal habitats is as nurseries for the juveniles of fish. Many of the studies that have assessed the nursery function of structurally complex coastal habitats have compared seagrass with unstructured sand and mud and as such, seagrass has emerged as the most important coastal nursery habitat for juvenile fishes. Although considerably less work has focussed on the nursery provision of structurally complex macroalgae within coastal nursery seascapes, recent work has started to highlight that the nursery provision of canopy-forming macroalgae may in fact be comparable with that of seagrass. This review collates research published on the important nursery role of macroalgae within both tropical and temperate coastal seascapes and highlights the importance of smaller canopy-forming brown algae from the Fucalean genera (particularly Sargassum spp.) as core nursery areas for juvenile fishes, particularly emperors (Lethrinidae), rabbitfishes (Siganidae), wrasse and parrotfishes (Labridae), goatfishes (Mullidae), groupers (Serranidae), surgeonfish (Acanthuridae) and damselfish (Pomacentridae) within tropical back-reef systems. Similarly, in temperate nursery seascapes, fucoid (Cystoseira spp.) and macroalgae-dominated reefs were important nursery habitats for damselfish (Chromis chromis), groupers and numerous species of wrasse and sparids (Sparidae). Although the overall density of juvenile fish was not shown to be higher in kelp relative to other temperate nursery habitats, kelp was important in the recruitment of Notolabrus celiodotus (wrasse), Paralabrax clathrus (Serranidae), Brachyistius frenatus (Embiotocidae), Heterostichus rostratus (Clinidae) and Sebastes spp. (Scorpaenidae). Although not interchangeable (fish communities were often different), the nursery function of structurally complex macroalgae was found to be similar to that of seagrass in both temperate and tropical seascapes.

Spawning time of black sea bream Acanthopagrus schlegelii, related to underwater photoperiodism in oyster farms.

The embryonic development times, spawning timing and hatching rates of the black sea bream Acanthopagrus schlegelii were examined to investigate the potential effect of seawater temperature, tides and photoperiod on the reproductive rhythm of this species in Hiroshima Bay, Japan. Low temperatures decreased hatching rates and extended the hatching time, and the minimum temperature threshold for hatching was 15°C. Back-calculated spawning times indicated that the peak of spawning occurred just before sunset and the reduction in diurnal light intensity around the oyster rafts acted as a trigger for spawning. In contrast, no correlation was found between spawning rhythms and tidal cycle. The results highlight the important role of oyster farms in the reproductive cycle and population dynamics of A. schlegelii in Hiroshima Bay, the main spawning ground for this species in Japan. The study findings provide insights for the sustainable management of this important sparid species.

Diversity and structure of sparids external microbiota (Teleostei) and its link with monogenean ectoparasites

BackgroundAnimal-associated microbial communities appear to be key factors in host physiology, ecology, evolution and its interactions with the surrounding environment. Teleost fish have received relatively little attention in the study of surface-associated microbiota. Besides the important role of microbiota in homeostasis and infection prevention, a few recent studies have shown that fish mucus microbiota may interact with and attract some specific parasitic species. However, our understanding of external microbial assemblages, in particular regarding the factors that determine their composition and potential interactions with parasites, is still limited. This is the objective of the present study that focuses on a well-known fish-parasite interaction, involving the Sparidae (Teleostei), and their specific monogenean ectoparasites of the Lamellodiscus genus. We characterized the skin and gill mucus bacterial communities using a 16S rRNA amplicon sequencing, tested how fish ecological traits and host evolutionary history are related to external microbiota, and assessed if some microbial taxa are related to some Lamellodiscus species.ResultsOur results revealed significant differences between skin and gill microbiota in terms of diversity and structure, and that sparids establish and maintain tissue and species-specific bacterial communities despite continuous exposure to water. No phylosymbiosis pattern was detected for either gill or skin microbiota, suggesting that other host-related and environmental factors are a better regulator of host-microbiota interactions. Diversity and structure of external microbiota were explained by host traits: host species, diet and body part. Numerous correlations between the abundance of given bacterial genera and the abundance of given Lamellodiscus species have been found in gill mucus, including species-specific associations. We also found that the external microbiota of the only unparasitized sparid species in this study, Boops boops, harbored significantly more Fusobacteria and three genera, Shewenella, Cetobacterium and Vibrio, compared to the other sparid species, suggesting their potential involvement in preventing monogenean infection.ConclusionsThis study is the first to explore the diversity and structure of skin and gill microbiota from a wild fish family and present novel evidence on the links between gill microbiota and monogenean species in diversity and abundance, paving the way for further studies on understanding host-microbiota-parasite interactions.

First Skeletal Fossil Record of the Red Seabream Pagrus major (Sparidae, Perciformes) from the Late Pleistocene of Subtropical West Pacific, Southern Taiwan.

Fish fossils are only occasionally found in Taiwan, and such fossils are rarely appropriately analyzed and described. Despite their sparse records, several Plio-Pleistocene localities rich in marine organisms have yielded well-preserved specimens, potentially providing insight into the rarely identified fish fauna in the tropical-subtropical West Pacific. We describe a sandstone nodule containing fish skeletons from the Late Pleistocene Szekou Formation in southern Taiwan. The specimen includes nearly complete left jaws, fragmentary right jaws, and part of the anterior body. The distinct dentition of the specimen suggests it to be a member of Sparidae family. Further morphological analysis based on dentition and a comparison with 153 recent specimens belonging to 14 sparid species in the area enabled us to assign the fossil to the species Pagrus major. We found that the characteristic sparid tooth patterns are useful in generic determination, at least in Taiwan. The occurrence of the specimen is the first evidence of P. major in the region. Finally, the specialized tooth pattern and the estimated size indicate that the fish was a middle-to-top predator that fed on small fish and invertebrates in a neritic lagoonal environment.

Otolith mass asymmetry in three sparid fish species collected from the Iraqi waters

Saccular otolith mass asymmetry is examined in three sparid fish species, Acanthopagrus bifasciatus, A. arabicus, and Sparidentex hasta collected from Khor Abdullah at the North Persian Gulf. This characteristic was computed as the disparity between the weight of the right and left otoliths divided by mean otolith weight in the three sparid species investigated. According to the previous cases obtained on another symmetrical fish species, the absolute value of x in these species does not determine by fish length and otolith growth ratio, while the absolute rate of otolith weight disparity is boosted with the fish length. The estimate of x was between -0.2 and +0.2. Otolith mass asymmetry can show some growth disorder of fish owing to environmental influence.

First linkage maps and a pilot QTL analysis for early growth performance in common dentex (Dentex dentex) and sharpsnout seabream (Diplodus puntazzo)

Two potential candidate species for the Mediterranean aquaculture–the common dentex (Dentex dentex) and the sharpsnout seabream (Diplodus puntazzo)-are used in the present study in order to depict their genetic architecture for the first time. We have constructed the first linkage maps for both species using SNP markers derived from ddRAD sequencing. The quality of the maps produced was verified from comparative analysis with the most studied and phylogenetically related sparid species, the gilthead sea bream (Sparus aurata). A high genetic similarity was detected, based on the high number of alignments of the two new species against the reference genome of the gilthead seabream. Furthermore, a pilot study for QTL analysis per species was performed using phenotypic measurements at the juvenile stage (approximately 2 g) and revealed putative genomic areas which affect juvenile growth performance. One of those areas was located close to a candidate gene (ANGPTL6 gene) which affects growth performance. The present study improves our knowledge on the genetic architecture of those two species by presenting not only the first linkage maps, but also by providing some indications for growth performance QTL. The results can be used as a starting point to initiate further research for the genetic improvement of these two new species.

Larval rearing and ontogeny of digestive enzyme activities in yellowfin seabream (Acanthopagrus latus, Houttuyn 1782)

The present research was conducted to provide insight into digestive larval capacity in Acanthopagrus latus larvae from hatching up to 30 days after hatching (DAH). Newly hatched larvae were stocked into six 300-L cylindrical polyethylene tanks at a density of larvae 50 larvae/L and reared by means of the green water system using Nannochloropsis oculata (0.5 × 106/mL). After mouth opening, larvae were fed with rotifers (5–16 individual/mL) from 2 to 20 DAH; then, Artemia nauplii (0.5–3.0 individuals/mL) were offered to larvae from 18 to 30 DAH, meanwhile a commercial microdiet was offered to larvae from 25 to 30 DAH. Larval performance in terms of growth and survival, and the assessment of the activity of selected digestive enzymes ontogeny of digestive enzymes activities was evaluated in larvae sampled at 0 (hatching), 7, 15, 22 and 30 DAH. Larvae showed an exponential growth characterized by two different growth stanzas, a first one characterized by slow growth rates comprised between hatching to 15 DAH (4.7 ± 0.2 mm), followed by a period of faster growth rates between 16 and 30 DAH (7.5 ± 0.6 mm). The activities of the brush border (alkaline phosphatase, ALP) and cytosolic (leucine-alanine peptidase, LAP) enzymes, as well as those of the pancreatic ones like total alkaline proteases, bile salt-activated lipase and α-amylase were detected from the mouth opening stage. Total activities of pancreatic and gastric enzymes increased with larval growth showing an enhancement of digestive capacities with larval age and size. The intestinal maturation in A. latus as assessed by the ratio of AP to LAP did not occur as expected by end of the first month of life suggesting the complete establishment of digestive luminal processes may take place at older ages. This study related to the growth patterns and ontogenic changes in activity of pancreatic, gastric and intestinal enzymes in A. latus and their nutritional regulation may be considered as the first step for improving the larviculture, as well as assessing and refining the nutritional requirements during the larval and early juvenile stages of this sparid species.

Herbivory on the Invasive Alga Caulerpa cylindracea: The Role of Omnivorous Fishes

Herbivory has long been considered an important component of biotic resistance against macroalgae invasions in marine habitats. However, most of the studies on herbivory of invasive algae refer only to consumption by strictly herbivorous organisms, whereas consumption by omnivorous species has been largely ignored and rarely quantified. In this study, we assess whether the commonest omnivorous sparid species in the Mediterranean Sea are consuming the highly invasive alga, Caulerpa cylindracea, and determine both, its importance in their diet and their electivity toward it as a source of food. Our results confirm that three of the four fish species studied regularly consume C. cylindracea, but in most cases, the importance of C. cylindracea in the diet is low. Indeed, the low electivity values indicate that all species avoid feeding on the invasive alga and that it is probably consumed accidentally. However, despite animals and detritus being the main food for these sparid species, several individual specimens were found to have consumed high amounts of C. cylindracea. This suggests a potential role that these fish species, being really abundant in shallow rocky bottoms, may play in controlling, to some extent, the abundance of the invader.

Dentex dentex Frauds: Establishment of a New DNA Barcoding Marker

The common dentex (Dentex dentex (Linnaeus, 1758)) is an iconic fish in the Mediterranean diet. Due to its commercial and organoleptic importance, this sparid is highly appreciated in European markets and is often subjected to species substitution frauds. Comparative mitogenomics is a suitable approach for identifying new and effective barcode markers. This study aimed to find a molecular tag useful for unequivocally discriminating the sparid species D. dentex. The comparison of the complete mitochondrial DNA (mtDNA) sequences of 16 sparid species allowed us to highlight the potential of the NAD2 gene for direct identification purposes. Common dentex-specific primers were created and successfully evaluated by end-point and real-rime PCR (Polymerase Chain Reaction) for several fish species, achieving amplification only in the D. dentex. The method proposed in this study appears fast, simple, and inexpensive and requires affordable instrumentation. This approach provides unambiguous results for the common dentex authentication without the sequencing step. The presence/absence assay for D. dentex can be executed in a few hours of lab work. Therefore, national authorities responsible for food safety and traceability could apply and make full use of DNA-testing methods for deterring operators from false seafood declarations.

A Rapid Method for the Identification of Fresh and Processed Pagellus erythrinus Species against Frauds.

The commercialization of porgies or seabreams of the family Sparidae has greatly increased in the last decade, and some valuable species have become subject to seafood substitution. DNA regions currently used for fish species identification in fresh and processed products belong to the mitochondrial (mt) genes cytochrome b (Cytb), cytochrome c oxidase I (COI), 16S and 12S. However, these markers amplify for fragments with lower divergence within and between some species, failing to provide informative barcodes. We adopted comparative mitogenomics, through the analysis of complete mtDNA sequences, as a compatible approach toward studying new barcoding markers. The intent is to develop a specific and rapid assay for the identification of the common pandora Pagellus erythrinus, a sparid species frequently subject to fraudulent replacement. The genetic diversity analysis (Hamming distance, p-genetic distance, gene-by-gene sequence variability) between 16 sparid mtDNA genomes highlighted the discriminating potential of a 291 bp NAD2 gene fragment. A pair of species-specific primers were successfully designed and tested by end-point and real-time PCR, achieving amplification only in P. erythrinus among several fish species. The use of the NAD2 barcoding marker provides a rapid presence/absence method for the identification of P. erythrinus.

Acanthopagrus datnia (Hamilton, 1822), a senior synonym of Acanthopagrus longispinnis (Valenciennes, 1830) (Perciformes: Sparidae)

The taxonomic status of the Bay of Bengal nominal sparid species Coius datnia Hamilton, 1822 and Acanthopagrus longispinnis (Valenciennes, 1830) are reviewed and investigated both morphologically and genetically. Because of inadequate description and no type specimen, Coius datnia has recently been considered to belong to Sparidentex, a genus without molarifom teeth. Critical examination of the original description and examination of specimens from the type locality and adjacent areas reveal that Coius datnia belongs to Acanthopagrus, a genus with an inner series of molars. Furthermore, examination of specimens previously recognized as Acanthopagrus longispinnis (Valenciennes 1830), and recent collection of fresh specimens from lower Ganges estuary in Bangladesh, show that morphological differences between Acanthopagrus datnia and A. longispinnis are minor, and they are genetically identical. The longer second anal-fin spine in A. longispinnis (>21% SL) is, in fact, a feature of some younger A. datnia. Accordingly, A. datnia is regarded as a senior synonym of A. longispinnis, and is distinguished from its congeners by the presence of 12 dorsal-fin spines (rarely 11 or 13), 3½ scale rows between the fifth dorsal-fin spine base and lateral line, pelvic and anal-fins pale yellow to yellow with black streaks present in the interradial membranes of anal-fin rays, and caudal fin grey or yellowish grey. A neotype (and neogenotype) has been designated for Acanthopagrus datnia (Hamilton, 1822).

A phylogenetic comparative analysis on the evolution of sequential hermaphroditism in seabreams (Teleostei: Sparidae)

The Sparids are an ideal group of fishes in which to study the evolution of sexual systems since they exhibit a great sexual diversity, from gonochorism (separate sexes) to protandrous (male-first) and protogynous (female-first) sequential hermaphroditism (sex change). According to the size-advantage model (SAM), selection should favour sex change when the second sex achieves greater reproductive success at a larger body size than the first sex. Using phylogenetic comparative methods and a sample of 68 sparid species, we show that protogyny and protandry evolve from gonochorism but evolutionary transitions between these two forms of sequential hermaphroditism are unlikely to happen. Using male gonadosomatic index (GSI) as a measure of investment in gametes and proxy for sperm competition, we find that, while gonochoristic and protogynous species support the predictions of SAM, protandrous species do not, as they exhibit higher GSI values than expected even after considering mating systems and spawning modes. We suggest that small males of protandrous species have to invest disproportionally more in sperm production than predicted not only when spawning in aggregations, with high levels of sperm competition, but also when spawning in pairs due to the need to fertilize highly fecund females, much larger than themselves. We propose that this compensatory mechanism, together with Bateman’s principles in sequential hermaphrodites, should be formally incorporated in the SAM.