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Assessing genetic diversity within species is key for conservation strategies in the context of human-induced biotic changes. This is important in marine systems, where many species remain undescribed while being overfished, and conflicts between resource-users and conservation agencies are common. Combining niche modelling with population genomics can contribute to resolving those conflicts by identifying management units and understanding how past climatic cycles resulted in current patterns of genetic diversity. We addressed these issues on an undescribed but already overexploited species of sardine of the genus Harengula. We find that the species distribution is determined by salinity and depth, with a continuous distribution along the Brazilian mainland and two disconnected oceanic archipelagos. Genomic data indicate that such biogeographic barriers are associated with two divergent intraspecific lineages. Changes in habitat availability during the last glacial cycle led to different demographic histories among stocks. One coastal population experienced a 3.6-fold expansion, whereas an island-associated population contracted 3-fold, relative to the size of the ancestral population. Our results indicate that the island population should be managed separately from the coastal population, and that a Marine Protected Area covering part of the island population distribution can support the viability of this lineage. [ABSTRACT FROM AUTHOR]

ABSTRACT This study aimed to evaluate the effect of different levels of omega-3 polyunsaturated fatty acids (n-3 PUFA) in the diet of Sardinella brasiliensis on their hematological parameters. A total of 375 fish were distributed in 15 experimental units to evaluate the effects of the diet on their blood for 45 days. The levels of n-3 PUFA added in the diet were 0, 0.3, 0.6, 0.9, and 1.2% of the lipid fraction. These values represent the total percentage of n-3 PUFA in the lipid fraction of the diet, and 0% n-3 PUFA was used as the negative control. Five fish from each experimental unit were sampled at the end of the experiment for hematological analysis, and the parameters measured include the total number of erythrocytes, hematocrit percentage, hemoglobin and glucose concentration and differential leukocyte count. Higher numbers of circulating eosinophils were observed in fish fed 0.3% and 1.2% n-3 PUFA. Although no significant differences were observed in several of the parameters, the results demonstrate that the health of the sardines was not affected by the addition of n-3 PUFA in their diet. It should be emphasized that this is the first study with emphasis on the blood analysis of S. brasiliensis.

Thread herrings (Opisthonema spp.) are economically important fish species in the Tropical Eastern Pacific. Knowledge of the parasitofauna of commercially exploited species is useful as it can increase our understanding of fish biology and ecology. However, our knowledge of the parasites of Opisthonema spp. is limited. During a fisheries exploration survey in April 2022, samples of Opisthonema bulleri and O. libertate were collected from three oceanographic stations in the Gulf of Tehuantepec in the Mexican Pacific. Parasitological analysis of these materials uncovered four parasite species: Myosaccium ecaude (Trematoda), Cribromazocraes sp. (Monogenea), Pseudoterranova sp. (Nematoda), and an unidentified crustacean of the family Pennellidae (Copepoda). All these species appeared rarely, except for M. ecaude, which reached a prevalence of 100%. The median intensity of M. ecaude infection was significantly higher in O. bulleri than in O. libertate. We analyzed the relationship between parasitic infection intensity and three host traits (fork length, body weight, and age). Only body weight showed a significant positive association with intensity. Future studies are required to analyze the possible effects of seasonality, locality, and host ontogeny on the occurrence of M. ecaude in thread herrings in the Tropical Eastern Pacific.

Thread herrings (Opisthonema spp.) are economically important fish species in the Tropical Eastern Pacific. Knowledge of the parasitofauna of commercially exploited species is useful as it can increase our understanding of fish biology and ecology. However, our knowledge of the parasites of Opisthonema spp. is limited. During a fisheries exploration survey in April 2022, samples of Opisthonema bulleri and O. libertate were collected from three oceanographic stations in the Gulf of Tehuantepec in the Mexican Pacific. Parasitological analysis of these materials uncovered four parasite species: Myosaccium ecaude (Trematoda), Cribromazocraes sp. (Monogenea), Pseudoterranova sp. (Nematoda), and an unidentified crustacean of the family Pennellidae (Copepoda). All these species appeared rarely, except for M. ecaude, which reached a prevalence of 100%. The median intensity of M. ecaude infection was significantly higher in O. bulleri than in O. libertate. We analyzed the relationship between parasitic infection intensity and three host traits (fork length, body weight, and age). Only body weight showed a significant positive association with intensity. Future studies are required to analyze the possible effects of seasonality, locality, and host ontogeny on the occurrence of M. ecaude in thread herrings in the Tropical Eastern Pacific. [ABSTRACT FROM AUTHOR]

This study assessed the growth, mortality and exploitation rate of Sardinella aurita in the New Calabar River. A total of 513 specimens of S. aurita were collected from artisanal fishers and assessed between March 2020 and February 2021.For statistical analysis, FiSAT II software was used. At asymptotic length (L∞) = 21.73 cm, growth rate (K) = 0.95 yr-1, longevity (Tmax) = 2.68 yrs., theoretical age at birth (t0) = -0.48 yrs., and growth performance index (Φ′) = 2.65. Length at first capture (Lc50 = 15.06 cm) was lower than length at first maturity (Lm50 = 21.12 cm). Mortality parameters revealed a total mortality rate (Z) = 3.03 yr-1, a natural mortality rate (M) = 1.42 yr-1, and a fishing mortality rate (F) = 1.61 yr-1. This indicates that S. aurita in the study area has a fast growth rate, small attained size, delayed sexual maturation, and high natural mortality. The exploitation rate (E) was 0.53. S. aurita was found to be experiencing optimum exploitation. Therefore, to prevent overfishing, sustainable fisheries measures should be adopted, and these include monitoring of fishing efforts and implementation and enforcement of increased mesh size to sustain the fishery of S. aurita in the New Calabar river.

Based on research 1995–2020, abundant and potentially commercial fish in Russian watersof the Chukchi Sea have been identified. In total, 72 species were recorded in trawl catches, 16 species from six families were abundant, among which smelts (Osmeridae), salmons (Salmonidae), and herrings (Clupeidae) accounted for an average of 1.5, 0.2, and 0.1% of the total commercial marine fish biomass, respectively. For the species of the analyzed families, the size-age and weight characteristics, features of linear and weight growth, timing, scale and conditions of spawning were considered. The biological indicators of fish from the Chukchi and Bering seas and other water bodies were compared. Saffron cod Eleginus gracilis, Arctic rainbow smelt Osmerus mordax dentex, Pacific cod Gadus macrocephalus, Greenland halibut Reinhardtius hippoglossoides, and some species of sculpins were represented mainly by juveniles and immature individuals, older fish appeared in climatically warm years. Walleye pollock Gadus chalcogrammus, Pacific salmons, Alaska plaice Pleuronectes quadrituberculatus, and starry flounder Platichthys stellatus were characterized by the presence of older individuals. In polar cod Boreogadus saida, Bering flounder Hippoglossoides robustus, yellowfin sole Limanda aspera, Sakhalin sole L. sakhalinensis, longhead dab L. proboscidea, Pacific herring Clupea pallasii, Pacific capelin Mallotus villosus catervarius, and warty sculpin Myoxocephalus verrucosus smaller body sizes were recorded for the specimens caught at the Chukchi Sea shelf comparing to those from the Bering Sea. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate body shape variations of Alosa braschnikowi populations in three localities of the Caspian Sea using geometric morphometric method. So that, 216 specimens were caught from three regions from west to east, including Guilan (Anzali), Mazandaran (Sari) and Golestan (Miankaleh). Shape data was extracted using 15 landmark points on 2-D pictures of specimens. The PCA, DFA analyses and cluster analysis based on Euclidean square distances were used to examine shape differences among the three populations. The results showed that there was a significant difference between the studied populations in terms of body shape (p

Fish parasite communities can be directly influenced by characteristics of host species. However, little is known about the host-parasite relationships in commercially important fish of the southeastern Atlantic. To address this knowledge gap, a comparative analysis of the parasite communities of three sympatric Clupeiformes was conducted. Cetengraulis edentulus (Engraulidae), Opisthonema oglinum (Clupeidae) and Sardinella brasiliensis (Clupeidae) were collected from an estuarine lagoon near Rio de Janeiro, Brazil. Prevalence, abundance and aggregation were estimated for infrapopulations; richness, diversity, evenness and dominance for infracommunities. The three component communities were compared using both quantitative and qualitative components. Canonical discriminant analysis was used to determine if a host population could be characterised by the component community of its parasites. Multivariate models revealed that host species, a proxy for diet and phylogenetic relationships, was the main factor influencing the composition of parasite infracommunities. Diet was found to be the main factor shaping the communities of endoparasites, in which digeneans were dominant and best indicator of host population. Ectoparasites (copepods, isopods and monogeneans) displayed strong host-specificity with some species restricted to a single host population. The similarity of the component communities of the two clupeid populations demonstrated the influence of host phylogeny. Parasite infracommunities exhibited low diversity and high dominance, with many taxa restricted to a single host species (specialists) and few occurring in more than one (generalists). Host phylogeny and by extension, diet, morphology and coevolution with parasites appear to be important factors in determining the host-parasite relationships of clupeiform fish in the southeastern Atlantic. [ABSTRACT FROM AUTHOR]

Recent estimates of the size at first maturity (L 50) of Sardinella brasiliensis showed contradictory results with a decreasing in the fish stock biomass encompassed by increasing values of L 50. The methodological approach used hereby allowed to separate sardines classified in the virginal maturity stage from those categorized in the recovery stage, and ready for one next spawning event. This study evaluated the hypothesis of the existence of separated stocks experiencing distinct environmental conditions and fishing pressures which may have altered L 50 estimates using a robust dataset based on biological samples collected along the entire species distribution area in the southeast-south Brazilian coast [Rio de Janeiro (RJ), São Paulo (SP), Paraná (PR), Santa Catarina (SC) and Rio Grande do Sul (RS)] between 2000 and 2018. A reclassification of the gonadal maturity stages provided a more realistic estimate of L 50. Combining biological, reproductive, fishing data and the mean temperature of the catch (MTC), the leave-one-out classification correctly re-assigned individuals with an overall accuracy of 85% [100% (RJ), 45% (SP), 99% (PR), 99% (SC) and 82% (RS)]. The connectivity between the local populations of S. brasiliensis off RJ (23°S) and the southern populations is limited, contrasting to spatial structured semi-discrete population-units found between SP and RS (24°S-30°S). The northern extreme population-unit (RJ, 22°S-23°S) showed an expressive reduction of L 50 , and a negative correlation was detected between the increasing MTC values and the abundance of early maturing individuals and recruits of the species. Stock specific L 50 estimates seemed to act as indicators of long term environmental fluctuations. • A long-term assessment of S. brasiliensis was conducted using a novel methodology • The study distinguishes 2 population-units: northern (22-23°S) and southern (24-30°S) • The northern population shown a notable reduction of the size at first maturity (L 50) • L 50 estimates correlated with increased mean temperature of the catch • Stock-specific L 50 may be used as indicator of long-term environmental fluctuations [ABSTRACT FROM AUTHOR]

Clupeiformes (generally known as herrings, shads and sardines) with a synapomorphy of recessus lateralis are globally distributed marine, freshwater and diadromous species classified in seven families including the family Clupeidae. In this study, a comparative analysis of the vertebral column and caudal skeleton of twelve clupeid species was conducted on the basis of X‐ray imaging and usual staining method of bones and cartilages. Several osteological features including number of principal branched caudal rays bearing with hypurals on both lobes of the caudal‐fin; number, length, arrangement and shape of epural bones; shape and length of haemal and neural spines of the penultimate vertebrae 2, 3 and 4; length and shape of parhypural; length and shape of neural arch of the urostyle; distribution of the dorsal and procurrent rays, and fusion of parhypural with preural centrum 1 (PU1) were investigated and a detailed account of these structures were provided. The results reveal that the neural spine of the 2nd, 3rd and 4th penultimate vertebrae (NSPU2, NSPU3 and NSPU4) was generally narrow and broad in lower and pointed at upper part with some variation in the size and position related to the dorsal edge of the body in different taxa. The neural arch of the urostyle (Na) has been observed as spindle, lance‐like or knife‐like. It is usually long (≥1/2 length of the NSPU2) with some modification in the studied species. Two or three curved, straight, cone‐shape or pin‐shaped epurals were found in all species with the same number in congeneric species. Opisthural cartilage (O) lays between HYP6 and PLS anteriorly, located at the tip of PLS or traversed horizontally. The presence of this cartilage made a gap between first (longest) and second unbranched caudal rays in upper part of caudal‐fin. It showed six varied shapes (e.g. fusiform, golf club‐like, horn shape, trapezoid shape, crescent and triangle) with different size in comparison with HYP6. This comparative study revealed that some osteological characters such as shape and position of opisthural cartilage, shape of neural arch of the urostyle, and number of epurals could be used as suitable features for the identification of the studied clupeids at the species and genus levels. The improved knowledge of the skeletal structures provided here, can also facilitate the correct identification of clupeid fossils. [ABSTRACT FROM AUTHOR]

The Brazilian sardine (Sardinella brasiliensis) sustains the most important pelagic fishery off Brazilian waters. The present study evaluated the existence of distinct population-units inferred from body geometric morphometrics and otolith shape analyses using two and three-year-old individuals collected in Rio de Janeiro and Santa Catarina, the two main Brazilian fishery grounds. Univariate and multivariate statistics were performed for the entire dataset and separated by age groups. Re-classification success for combined ages achieved an overall re-classification rate of 84% and 89% for body and otolith signatures, respectively. Moreover, the combination of both techniques improved the overall re-classification success to 93%. However, when both techniques were conducted by age group, it allowed to unravel a more detailed population structure scenario, and a complete group separation (100% re-classification success) was obtained using otolith shape analyses for two-year-old individuals. Both techniques indicated the existence of two different population-units considering the Brazilian geographical extremes of the species' fishing area. Such regional differences are probably related to distinct oceanographic conditions affecting the feeding regime and fish growth. This study clearly shows that S. brasiliensis caught off southeast-south Brazil corresponds to two distinct population-units, and recommends a finer regional fishery management for the species. [ABSTRACT FROM AUTHOR]

Many anadromous (and semi-anadromous) fish species, which migrate from marine to freshwater ecosystems to spawn and to complete their life cycle, are currently threatened by habitat degradation in the upper parts of estuaries and rivers, where spawning and juvenile nursery areas occur. This situation pertains to Nematalosa vlaminghi, a semianadromous gizzard shad (Clupeidae: Dorosomatinae) endemic to south-western Australia. More information on the biology of N. vlaminghi is required for its effective management and conservation. This study estimated growth, longevity and natural mortality of N. vlaminghi. Ages were determined by counting validated annual growth increments in thin sections of sagittal otoliths. Fish were sampled in the Swan-Canning Estuary, which historically hosted the main commercial fishery for N. vlaminghi. Since the late 1990s, however, only very minor catches of this species have been taken from this estuary and none since 2007. Given the essentially unexploited state of the current population, the estimate of total mortality (Z, y-1 ) from the catch curve analysis in this study provides a direct estimate of natural mortality (M, y-1 ) for N. vlaminghi. Somatic growth during this study was substantially slower than that historically reported for N. vlaminghi. Various processes operating in this estuary since the 1970s may have contributed to slower growth, including increased hypoxia, higher primary productivity due to eutrophication and cessation of fishing for N. vlaminghi. The maximum observed age of 19.8 years for N. vlaminghi is the highest reported for any gizzard shad globally and one of the highest reported for any clupeid species. This exceptional longevity is likely part of a life-history strategy that allows N. vlaminghi, which exhibits substantial variation in annual recruitment success, to persist in the intermittently closed estuaries of south-western Australia where environmental factors, including low flow and hypoxia, can create unfavourable conditions for reproduction for extended periods. [ABSTRACT FROM AUTHOR]

The diagnostic features of otolith morphology were provided for the clupeid fishes of the Iranian brackish and marine resources to be used as diagnostic features for the identification of clupeids diversity in these regions. Fish individuals belong to 20 species belong to 13 genera, and four families were collected from the Caspian Sea, the Persian Gulf and the Makran zone of the Oman Sea. Overall, seven otolith morphotypes were distinguished, that is lanceolated (45%), fusiform (20%), boot‐like (15%) and clamp‐like, pentagonal, elliptic and rectangular (each 5%, respectively). The univariate analysis showed that all variables except shape index [sulcus area (SS)/otolith area (OS)] and ROx (roundness) were significantly different among the clupeid species. The interspecific relationships of the otoliths were analysed based on the data of otolith morphology and otolith shape indices. Both dendrograms showed somehow an obvious separation among the studied species. However, the interspecific relationships in the dendrogram based on the otolith morphology have a better resolution. These phenotypic relationships based on otolith morphology among the studied clupeids are largely consistent with the previous hypothesis on the systematics of these fishes and emphasized that the morphological and morphometric features of the otolith, which are highlighted in this study, could be adequately used as diagnostic features for the identification of clupeids diversity. [ABSTRACT FROM AUTHOR]

A new species of Bacciger Nicoll, 1914, is described from the digestive tract of the American gizzard shad, Dorosoma cepedianum (Lesueur), in some inland waterways of Mississippi, and in Mobile Bay, Alabama, U.S.A. This now represents the only nominal species in the genus from the northwest Atlantic Ocean or inland tributaries of eastern North America north of Mexico. Two potentially close relatives that range in the northwest Atlantic Ocean are Baccigeroides ovatus (Price, 1934) Cutmore, Bray and Cribb, 2018, and Pseudobacciger manteriNahhas and Cable, 1964. The new species differs from Bo. ovatus mainly by having the genital pore opening immediately anteriad from the ventral sucker rather than far anteriad from it at the pharynx level, and from P. manteri mainly by having a distinct cirrus sac rather than having the terminal genitalia free in the parenchyma. The 3 genera are currently classified in the Faustulidae Poche, 1926. Although life cycles are unknown for the American species, evidence from life history of the related species Bacciger bacciger (Rudolphi, 1819) Nicoll, 1914, and Pseudobacciger harengulae (Yamaguti, 1938) Nahhas and Cable, 1964, combined with molecular phylogenetic evidence, indicate that the studied digeneans likely have a nonoculate trichocercous cercaria. We discovered sporocysts containing nonoculate trichocercous cercariae we identified as Cercaria rangiaeWardle, 1983, infecting the viscera of the Gulf wedge clam, Rangia cuneata (G. B. Sowerby I), in the Pascagoula River, Mississippi, U.S.A. We generated the internal transcribed spacer 2 (ITS2) region and a portion of the 28S rDNA gene from the new species and C. rangiae. Dissimilarity at both sequences demonstrated that the stages were not conspecific. Bayesian inference analyses applied separately to the ITS2 region, and the partial 28S rDNA gene, resulted in trees with similar topology, both depicting the new species and C. rangiae as sister taxa. The possible identity of C. rangiae and the phylogenetic relationships among species of Bacciger and related genera are discussed. We consider Bacciger lesteriBray, 1982, and Bacciger sprentiBray, 1982, incertae sedis in the Microphalloidea Ward, 1901. All other species of Bacciger, and species belonging in PseudobaccigerNahhas and Cable, 1964, and Baccigeroides Dutta, 1995, are transferred from the Faustulidae to the Gymnophalloidea Odhner, 1905, where their familial affinities remain incertae sedis. [ABSTRACT FROM AUTHOR]

Morphological studies are strong and instrumental for determining discreteness of the similar species and extensively used to identify differences between fish populations. A total of 216 specimens of Alosa braschnikowi were randomly collected by beach seine from three fishing regions along the southern Caspian Sea coasts, including some regions of Miankaleh, Sari and Anzali, in the fishing season during 2018-2019. The extracted landmark-points (body shape data) were submitted to a generalized Procrustes analysis (GPA) to remove nonshape data in PAST software. In the present study, the size effect was removed successfully by procrustes action in PAST software. Principal component analysis (PCA) was performed to summarize the variation among the specimens as few dimensions as possible. As a complement to discriminant analysis, morphometric distances among the three localities were inferred to cluster analysis by adopting the Euclidean square distance as a measure of dissimilarity method as the clustering algorithm. The dendrogram derived from cluster analysis of Euclidean square distances showed that the three populations of A. braschnikowi were distinct from each other in terms of morphometric characters. The Wilks' lambda tests of discriminant analysis indicated significant differences in morphometric characters of the three populations. The results of the present study demonstrated significant morphological differences between the three populations of A. braschnikowi. These differences in the three studied basins were mainly related to the characteristics of head and snout, body height, caudal peduncle, dorsal and anal fin base, which could be related to the hydraulic conditions and diet of the populations. [ABSTRACT FROM AUTHOR]

Tropical sardines and herrings (Family Clupeidae) form important fisheries resources in the Indo-West Pacific region. However knowledge of their biology and ecology is largely scattered across diverse localised studies. In addition, their challenging taxonomy due to numerous, morphologically similar species, coupled with data collected from dispersed, often small-scale and mixed species fisheries, creates difficulties for comparing species-level research and fisheries statistics across the region. This review considers four main groups of tropical marine clupeid species important for Indo-West Pacific fisheries—Sardinella (subg. Sardinella) species ('Round-bodied Sardinellas'), Sardinella (subg. Clupeonia) species ('Flat-bodied Sardinellas'), Amblygaster species ('Tropical Pilchards'), and Herklotsichthys and Escualosa species ('Tropical Herrings')—and collates and synthesises existing knowledge on early life history, reproduction, trophic biology, habitat associations and population dynamics. Most research on tropical clupeid biology and ecology in the Indo-West Pacific is concentrated on the Round-bodied Sardinellas (S. longiceps and S. lemuru) from a few major fishery locations; other species-groups have been studied sporadically across their distributions. Characteristics such as maximum size, life span, size at first maturity and some habitat associations are generally similar within species-groups and differ between groups. However differences within the same reported species highlight the importance of continued work to improve taxonomic identification. There remain substantial gaps in knowledge on all species-groups. Regular critical review of specific research topics, such as reproductive parameters and population dynamics, would assist to standardise methods and terminology used, enable consolidation and comparison of findings, identify local research agenda, and help build and improve research on these important tropical species. [ABSTRACT FROM AUTHOR]

Otoliths can be used to examine the migration history of fish individuals based on trace element concentrations in them. In order to verify migration patterns of Clupanodon thrissa and Nematalosa nasus (Clupeiformes: Clupeidae), Sr:Ca ratios in otoliths of 13 individuals (6 C. thrissa and 7 N. nasus) collected from Vietnam were examined. In addition, to provide guidelines for identification, the otolith morphology of the two species was comparatively illustrated. The otolith Sr:Ca ratios from the core to the edge ranged from 0 to 5.7 × 10-3 and 0 to 4.9 × 10-3 for C. thrissa and N. nasus, with an average of 1.8 × 10-3 and 2.3 × 10-3, respectively. The present data do not show typical anadromous profiles as the Sr:Ca ratio of the two species mostly fluctuates evenly from 0 to 4 × 10-3. These data suggest that the life cycles of the studied populations of C. thrissa and N. nasus are entirely completed in estuarine habitats. [ABSTRACT FROM AUTHOR]

The identification of fish stocks is the first step in management and conservation processes. The European Commission has established among others the Protected Geographical Indication (PGI) protection label in order to identify an agricultural product, raw or processed, for which quality, reputation or other characteristics are linked to its geographical origin. In the present study, the Greek Sardina pilchardus haplotypes found with three mitochondrial segments (COI, cytb, D-loop), were compared with the ones previously submitted in the databases, to test the uniqueness of the discovered Greek haplotypes for a future PGI definition. For all the three mtDNA markers, the discovered Greek haplotypes were found to be common with species' haplotypes all over the world. These results reinforce the aspect that a single sardine individual cannot be classified as coming from a certain population (Mediterranean or Atlantic), as most of the data (present and former) support a single evolutionary unit for sardines. [ABSTRACT FROM AUTHOR]

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Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sprat (Sprattus sprattus) is one of the most commercially exploited fish species in the Baltic Sea and expresses a pronounced seasonal migration pattern. Spawning takes place, among other places, in the Kiel Bight and Kiel Fjord in early summer. Juvenile sprat leave the nursery areas in late summer/early autumn to move to their feeding and overwintering grounds. What kind of orientation mechanisms sprat use for migration is not known yet. This study shows that juvenile sprat can use a time-compensated sun compass, heading towards the northeast, in the direction of their proposed overwintering grounds in Bornholm Basin. The sprats tested at the end of August oriented themselves in the predicted direction, whereas the sprats tested at the beginning of August only showed a random orientation. For the first time, this demonstrates the onset of migratory readiness in juvenile sprat, indicating the preparation for starting their migration., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

The Kelee shad (Hilsa kelee) is currently considered as the only representative species in the genus Hilsa (Clupeidae, Clupeiformes) with a wide distribution in almost all coasts of the Indian Ocean. Two marginal marine water bodies of the Indian Ocean, the Bay of Bengal and the Arabian Sea, are important fisheries areas for this fish. In this study, a comparison of genetic diversity of Kelee shad of these two important fisheries areas was conducted by applying a cross-species gene enrichment method. This was also the first challenge to discover the genetic diversity of this fish. Analysis of molecular variance results showed that the variation between groups is 10.85% and among individuals within populations contributed 89% variation. Nucleotide diversity results showed that Kelee shad populations are in almost stable condition and have a moderate population size. Nucleotide diversity of the Bay of Bengal and the Arabian Sea were almost similar; these were 0.012138 and 0.010831, respectively. Network, structure, and PCA results suggested that Kelee shad of the Bay of Bengal and the Arabian Sea have significant genetic differences. These two populations were separated from each other by a FST value of 0.10955 (p < 0.05). It is speculated that Southern India along with Sri Lanka and Ram bridge together with ancient climatic differences acted as means of isolation concerning Kelee shad populations between these two water bodies. Furthermore, from the maximum likelihood phylogenetic tree, it is established that the Arabian Sea can be regarded as the major stock of this species. [ABSTRACT FROM AUTHOR]

The amount of interspecific and ontogenetic variation in otolith shape among clupeid fishes from Japan was investigated to create a key to identify otoliths of these species found in the stomach contents of piscivorous predators, fossiliferous beds, and archaeological sites. The interspecific comparison with 12 species (Clupea pallasii, Etrumeus micropus, Herklotsichthys quadrimaculatus, Ilisha elongata, Konosirus punctatus, Nematalosa come, Nematalosa japonica, Sardinella aurita, Sardinella melanura, Sardinella zunasi, Sardinops melanostictus, and Spratelloides gracilis) revealed morphological variation in otolith shape, OL:OH and AL:RL ratios, rostrum, marginal structures, and features of the crista superior. Intraspecific changes were analyzed in two species (E. micropus and S. melanostictus), revealing ontogenetic changes in OL:OH ratio and consequently otolith shape as well as changes in marginal features. Overall, this study shows that the key morphological features can be used as diagnostic features for identification of clupeid otoliths. [ABSTRACT FROM AUTHOR]

Se recolectaron 21 muestras de Clupea (S.) bentincki de las capturas de la pesca comercial en la VIII Región de Chile (36°S Lat.) para analizar el contenido del estómago. Los alimentos más abundantes se identificaron como los géneros de diatomeas Skeletonema, Biddulphia, Coscinodiscus, Nitzchla y los géneros dinoflagelados Ceratium y Peridinum.

Unlike their marine counterparts, tropical freshwater clupeids receive little scientific attention. However, they sustain important fisheries that may be of (inter)national commercial interest. Africa harbours over 20 freshwater clupeid species within Pellonulini. Recent research suggests their most abundant parasites are gill-infecting monogenean flatworms within Kapentagyrus. After inspecting specimens of 12 freshwater clupeids from West and Central Africa, mainly sourced in biodiversity collections, we propose 11 new species of Kapentagyrus, which we describe using their haptoral and genital morphology. Because of their high morphological similarity, species delineation relies mostly on the morphometrics of anchors and hooks. Specifically, earlier, molecular taxonomic work indicated that the proportion between the length of the anchor roots, and between the hook and anchor length, is diagnostic. On average, about one species of Kapentagyrus exists per pellonuline species, although Pellonula leonensis harbours four species and Microthrissa congica two, while Microthrissa moeruensis and Potamothrissa acutirostris share a gill monogenean species. This study more than quadruples the number of known species of Kapentagyrus, also almost quadrupling the number of pellonuline species of which monogeneans are known. Since members of Kapentagyrus are informative about their hosts’ ecology, evolutionary history, and introduction routes, this enables a parasitological perspective on several data-poor African fisheries.

The family Clupeidae is believed to be represented by nine species in the Black Sea. However, this view is not generally accepted and the genus Alosa is one of the most challenging groups from taxonomic point of view. The phylogenetic relationships among three shad species (Alosa caspia, Alosa immaculata and Alosa tanaica) from Bulgarian marine waters were studied base on cytochrome b sequences. Totally, one hundred samples of the genus Alosa were examined. Five individuals with the most possible identification as Alosa tanaica formed a clade positioned basally to the other two species. A. caspia and A. immaculata formed a clade but being clearly distinct from one another. The results confirm that Cyt b sequences can be used for distinguishing species of the genus Alosa occurring in the Black Sea. [ABSTRACT FROM AUTHOR]

To assess potential filtration mechanisms, scanning electron microscopy was used in a comprehensive quantification and analysis of the morphology and surface ultrastructure for all five branchial arches in the ram suspension‐feeding fish, American shad (Alosa sapidissima, Clupeidae). The orientation of the branchial arches and the location of mucus cells on the gill rakers were more consistent with mechanisms of crossflow filtration and cross‐step filtration rather than conventional dead‐end sieving. The long, thin gill rakers could lead to a large area for the exit of water from the oropharyngeal cavity during suspension feeding (high fluid exit ratio). The substantial elongation of gill rakers along the dorsal‐ventral axis formed d‐type ribs with a groove aspect ratio of 0.5 and a Reynolds number of approximately 500, consistent with the potential operation of cross‐step filtration. Mucus cell abundance differed significantly along the length of the raker and the height of the raker. The mucus cell abundance data and the observed sloughing of denticles along the gill raker margins closest to the interior of the oropharyngeal cavity suggest that gill raker growth may occur primarily at the raker tips, the denticle bases, and the internal raker margins along the length of the raker. These findings will be applied in ongoing experiments with 3D‐printed physical models of fish oral cavities in flow tanks, and in future ecological studies on the diet and nutrition of suspension‐feeding fishes. Research Highlights: The morphology of American shad mouths is consistent with models of crossflow and cross‐step filtration rather than dead‐end sieving. The rib‐and‐groove arrangements of gill rakers in herrings and sardines may function as filtration engineering structures. [ABSTRACT FROM AUTHOR]

1.Marine protected areas (MPAs) are set up to conserve biodiversity, but their design is not always based on strictly scientific considerations. Ideally, an MPA should protect all key habitats necessary for a marine species to complete its life cycle. The identification of these key habitats is complex, especially during the early life of marine fishes.2.A widely distributed tropical and important low trophic‐level fish species, Spratelloides delicatulus (Clupeidae), was used to evaluate the significance of various coastal habitats for its larvae and juveniles in the Con Dao Archipelago MPA in Vietnam. Early stages (larvae and juveniles) were sampled monthly over one year (June 2016 to May 2017) using light traps in three main habitats (seagrass beds, coral reefs and harbour). The species was identified using morphometry and DNA barcoding. Age and growth variables were estimated using otolith daily growth increments.3.A total of 3,581 fish were caught. The species was not found in captures between January and February, directly linked to the decrease in seawater temperature and was most abundant from April to June. For a subsample of 248 fish (7–38 mm standard length), ages ranged from 7 to 108 days.4.Captures and back‐calculated birthdates using otolith daily increments showed that S. delicatulus spawns during the period of high seawater temperature, from March to October. The species colonizes all three habitats during the early stages (0–26 days old), with growth rate lowest on the seagrass beds. Nevertheless, the species occupies seagrass beds exclusively during the older stages.5.The conservation of seagrass beds in the Con Dao archipelago is essential for protection of juvenile stages of this species but this habitat is presently not included in the MPA patches. Establishment of a continuum of protected areas linking habitats, rather than the existing patches is needed to conserve the complete life cycle of this species in the Con Dao MPA. [ABSTRACT FROM AUTHOR]

• There was no consistent geographical structure along a north–south axis in either Kapentagyrus spp. • Results correspond to the previously reported near panmixia of both clupeid host species. • There was temporal differentiation between some of the populations of Kapentagyrus spp. • Recent population expansion in species of Kapentagyrus were assumed to be influenced by past lake level changes. • This is the first known documented hybridisation among dactylogyrid monogenean species. Lake Tanganyika, East Africa, is the oldest and deepest African Great Lake and harbours one of the most diverse fish assemblages on earth. Two clupeid fishes, Limnothrissa miodon and Stolothrissa tanganicae , constitute a major part of the total fish catch, making them indispensable for local food security. Parasites have been proposed as indicators of stock structure in highly mobile pelagic hosts. We examined the monogeneans Kapentagyrus limnotrissae and Kapentagyrus tanganicanus (Dactylogyridae) infecting these clupeids to explore the parasites' lake-wide population structure and patterns of demographic history. Samples were collected at seven sites distributed across three sub-basins of the lake. Intraspecific morphological variation of the monogeneans (n = 380) was analysed using morphometrics and geomorphometrics of sclerotised structures. Genetic population structure of both parasite species (n = 246) was assessed based on a 415 bp fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Overall, we observed a lack of clear geographical morphological differentiation in both parasites along a north–south axis. This lack of geographical population structure was also reflected by a large proportion of shared haplotypes, and a pattern of seemingly unrestricted gene flow between populations. Significant morphological and genetic differentiation between some populations might reflect temporal differentiation rather than geographical isolation. Overall, the shallow population structure of both species of Kapentagyrus reflects the near-panmictic population structure of both host species as previously reported. Morphological differences related to host species identity of K. tanganicanus were consistent with incipient speciation at the genetic level. Both parasite species experienced a recent demographic expansion, which might be linked to paleohydrological events. Finally, interspecific hybridisation was found in Kapentagyrus , representing the first case in dactylogyrid monogeneans. [ABSTRACT FROM AUTHOR]

Background. Species identification from recovered fish scales, e.g., from the sediment or stomach contents, has proven to be problematic for clupeid species. To ensure reliable species discrimination within Clupeidae, we attempted to reveal inter- and intra-specific, as well as, the intra-individual variability of scale shape in two sympatric clupeid species the European pilchard, Sardina pilchardus (Walbaum, 1792) and the round sardinella, Sardinella aurita Valenciennes, 1847. Our aim was to test, whether the landmark-based geometric morphometric method is reliable for species identification from mixed samples. Materials and methods. The specimens of European pilchard and round sardinella were collected between May and October 2014 from the Gulf of Ambracia, Greece. The scale samples were taken from ten body areas (marked by letters A–J) of 487 specimens in total. A multiple-step analysis was conducted on randomly selected blind samples. The differences between body areas were assessed with canonical variate analysis (CVA) and discriminant function analysis (DFA) to compute generalized Mahalanobis distances (D) and discriminant functions (T2), respectively. Results. The CVA based on the total scale samples showed that in sardinella, all body areas differed significantly from each other (D = 2.54 ± 0.79, P < 0.001) except for one (area I vs. J: D = 22.36, P = 0.085). In pilchard, two body area pairs represented non-significant group pairs (area D vs. G: D = 1.03, P = 0.12; and area F vs. G: D = 1.21, P = 0.06), whereas all other areas were significantly different (D = 2.43 ± 0.88, P = 0.003). At the last step of the blind sampling procedure, all scales were correctly classified by species with an average discrimination rate as high as 96.3%. Conclusion. In contrast to scale identification based merely on morphology, the geometric morphometric method is capable of detecting differences in scale shape from mixed samples that are unattainable with the former approach. Therefore, a more reliable and effective species identification can be accomplished from recovered scales, especially when discriminating species within the same family or genus.

Threadfin shad (Dorosoma petenense) is a schooling pelagic forage fish native to watersheds of the Gulf Coast of North America. Around 1962 it invaded the Sacramento-San Joaquin Delta from upstream reservoirs, where it was stocked to support sport fisheries. It quickly became, and continues to be, one of the most abundant fishes collected by ongoing monitoring programs in the delta. A substantial portion of the delta provides suitable abiotic habitat and so the species is widely distributed. However, in routine sampling it is most commonly collected and most abundant in the southeastern delta, where suitable abiotic habitat (relatively deep, clear water with low flow) coincides with high prey abundance. Apparent growth rate appears to be relatively fast with summer-spawned age-0 fish attaining fork lengths of 70 to 90 mm by the onset of winter. During fall months (September through December) apparent growth rate of age-0 fish has exhibited no long-term trend but has been negatively related to abundance, suggesting that density-dependent factors may be important to the population. Although abundance has fluctuated since its introduction almost five decades ago, it has recently dropped to persistent near-record lows since 2002, which has been coincident with similar declines for other pelagic species in the delta. The recent decline is apparent in two long-term monitoring programs, fish salvaged from the diversions of the state and federal water projects, and commercial fishing harvest. It appears that the decline is, at least in part, a function of fewer and smaller schools of threadfin shad encountered relative to the past. There was little evidence from the data examined for consistent stock-recruit or stage-recruit effects on the population. It is likely that a combination of abiotic and biotic factors regionally-focused where threadfin shad are most abundant, which may sometimes be episodic in nature, have a large effect on abundance. Focused studies and sampling of threadfin shad are lacking but are necessary in order to better understand population dynamics in the delta.

Faustula gangetica (Srivastava, 1935) Yamaguti, 1958 (Plagiorchiida: Faustulidae) from the Hilsa shad, Tenualosa ilisha (Hamilton) (Clupeiformes: Clupeidae), collected in the Arabian Gulf off Iraq between June and October 2014 is redescribed. We include details of the structures within the cirrus sac and provide further basic morphology for this species not previously available. Faustula ilishii (Srivastava, 1935) Yamaguti, 1958 is synonymized with F. gangetica. This is the first report of F. gangetica from the Hilsa shad in the Arabian Gulf. [ABSTRACT FROM AUTHOR]

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All around the world, diadromous fish are facing multiple anthropogenic pressures resulting in a global decline in these migratory species. In Gironde, the allis shad populations which were the most abundant in Europe are no exception and have dramatically declined since 2000. Failure in reproduction success is one of the proposed explanations for this collapse. In light of this, we studied the reproductive strategy of the allis shad populations in the Gironde watershed. We used an original methodology to define the thermal behavior of allis shad during reproduction using an electivity index for 14 years of field monitoring in two rivers, composed of daily reproduction activity and temperature. For the first time, this study deeply explores and defines the thermal preference of a shad species during the reproduction. A temperature preference between 14.5 °C and 23 °C by spawners during the reproduction was observed. Despite annual fluctuations, an overall similarity of temperature ranges between the two rivers was observed. The thermal preference matched with the thermal tolerance of early stages (16.2 °C to 24.8 °C) and confirms that allis shad spawners adopt behavioral rules of reproduction in order to maximize the survival of their offspring. The similarity of shad thermal behavior may indicate the phylogenetic basis of thermal preference for fish species. [ABSTRACT FROM AUTHOR]

Highlights • Sprattus fuegensis is the main marine pelagic resource in southern South America and the Patagonian and Malvinas stocks have been identified. • The schools detected in these two areas exhibited different school characteristics. • Fish forming the schools found in the Malvinas area were larger in size. • Malvinas Islands schools were larger in length, height, perimeter, area and volume. • The Patagonian schools evidenced higher S v values as compared to those found in the Malvinas area. Abstract Sprattus fuegensis is a physostomous species of fish belonging to the family Clupeidae that inhabits the waters of the South Western Atlantic Ocean (SWAO), between 47° and 55 °S. In the Pacific Ocean this species inhabits the Southern area of the Patagonia, 41°-55 °S. Previous studies suggest the occurrence of at least two stocks of Fuegian sprat in the SWAO, the Patagonian stock and the Malvinas stock. In the present study, data obtained during several cruises carried out during the spawning season of the stocks were employed to describe the sprat schools inhabiting the two areas. The differences found among them are briefly discussed in the context of their respective habitat characteristics. The acoustic descriptors extracted from the two groups of schools revealed significant differences. The Malvinas Islands schools were larger in length, height, perimeter, area and volume and also were located deeper in the water column. The Patagonian schools were of smaller size but evidenced higher average school S v values (∼ 6 dB). The Patagonian stock is associated with a larger number of denser but smaller schools, as compared with the Malvinas stock. Schools found in Malvinas area were composed of fish larger in size than those from the Patagonian coast. Trawl catches obtained in Patagonian waters ranged ca. 50–160 mm total length while fish caught in Malvinas Islands waters showed a body size of 90–220 mm TL. It is expected the information presented in this paper contributes to the knowledge of the sprat of the SWAO; one of the few fish populations that remain unexploited. [ABSTRACT FROM AUTHOR]

The basic biology and ecology of the South African east coast round herring Etrumeus wongratanai was investigated from samples of fish collected between 2013 and 2016. This species is short‐lived and reaches a maximum of 3 years of age, with rapid growth in its first year of life. It reproduces from June to December (austral summer) and condition factor was lowest in May through to August and increased from September, probably reflecting the physiological strain before and during spawning. Fish larvae were the most important food items consumed during summer, whereas eucalanid copepods were the most important prey at other times of the year. Stable‐isotope data suggest that there are gradual changes in the trophic level with increasing fish size, δ15N and δ13C values also differed between seasons. The results obtained here are compared with those of other Etrumeus species, regionally and globally. [ABSTRACT FROM AUTHOR]

The gross energy content of spawning batches and the microchemistry of sagittal otoliths in individual female bonga shad Ethmalosa fimbriata were compared between contrasting sampling sites at the Senegalese southern coast and inside the hypersaline Sine Saloum Estuary. Results show that females spawning in the estuary's middle reaches invested almost three times more energy into reproduction (115 ± 65 J g−1 body mass) than their neritic counterparts (39 ± 34 J g−1 body mass). Also, female otolith levels of Ba:Ca, Sr:Ca and Zn:Ca either differed significantly between study sites or could be linked to heterogeneous environmental variables. A quadratic discriminant function analysis provided evidence of segregated spawning populations of E. fimbriata in southern Senegalese waters. [ABSTRACT FROM AUTHOR]

The tropical shads of the genus Tenualosa are important and high-value commercial clupeid fishes in the Indo-Pacific region. Although there is difficulty in accurately identifying tropical shads based solely on morphology, we successfully identified T. ilisha and T. toli from Peninsular Malaysia and Borneo, which were confirmed by an analysis using 16S ribosomal RNA gene sequences. We propose that accurate identifications of tropical shad species should always include molecular genetic analysis for precise species confirmation. There is an urgent need for studies on the ecology, population dynamics, and conservation of these species in Malaysia. [ABSTRACT FROM AUTHOR]

Abstract Common sardine, Strangomera bentincki , support an important artisanal fishery along the Chilean coast; however, there is lack of knowledge of the early life history traits of this species. Using satellite-derived environmental conditions (sea surface temperature, SST, and chlorophyll- a), and otolith microstructure analysis of larval stages collected in coastal waters of central Chile, larval age, growth rates, and back-calculated yolk-sac absorption date patterns were analyzed for 2010–2013. SST varied from 11 to 20 °C and showed the highest values during austral summer 2013, whereas Chl- a varied between 0.2 and 66 mg m−3. The abundance of larval S. bentincki was similar during 2010 and 2011, decreased in 2012 but increased again in 2013 to similar densities of 2010 to 2011. Similarly, larvae collected during 2012 had the largest otoliths (radius, perimeter, area). Larval growth rates did not vary significantly among years and ranged between 0.32 and 0.42 mm day−1. From 2010 to 2011, a significant decrease occurred in the size-at-age of larval S. bentincki , and then, size-at-age was maintained until 2013. Back-calculated yolk-sac absorption dates differed among years and were delayed from winter to spring during 2012. The latter occurred in a period with significantly warmer waters. Additionally, SST and Chl- a concentration were not linearly related to the mean growth rates of larval S. bentincki. Highlights • Larval growth rates did not vary significantly among years • Larvae collected during 2012 had the largest otoliths (radius, perimeter, area) • From 2010 to 2011, a significant decrease occurred in the size-at-age of larvae • Yolk-sac absorption dates were delayed from winter to spring during 2012 • SST and Chl-a concentration were not linearly related to the mean growth rates [ABSTRACT FROM AUTHOR]

Larval fishes are sensitive to abiotic conditions and provide a direct measure of spawning success. The St. Clair – Detroit River System, a Laurentian Great Lakes connecting channel with a history of environmental degradation, has undergone improvements in habitat and water quality since the 1970s. We compared 2006–2015 ichthyoplankton community data with those collected prior to remediation efforts (1977–1978) to identify patterns in spatial and temporal variability. Both assemblages exhibited a predictable phenology, with taxa from the subfamily Coregoninae dominant in early spring followed by families Osmeridae, Percidae, and Moronidae (May–June) and Cyprinidae and Clupeidae (June–August). While higher densities of larval fish were found in the Detroit River, greater taxa richness and Shannon diversity were observed in the St. Clair River. System wide, 14 new taxa were observed in the 2000s study period. In addition, relative densities of two nonnative species, alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax), declined since the 1970s. Increased larval fish richness and decreased densities of nonnative taxa in the 2000s are consistent with improvements to environmental conditions. [ABSTRACT FROM AUTHOR]

The Indian river shad, Gudusia chapra (Hamilton, 1822), is a commercially important freshwater clupeid that contribute to the livelihood of subsistence and marginal fisheries in inland open waters of India and its adjacent countries. The present study was carried out on the growth and mortality of Indian River shad, Gudusia chapra (Hamilton, 1822) based on the commercial length-frequency data collected monthly during October 2014 to September 2015 of a large reservoir located in the border of Jharkhand and West Bengal. The ELEFAN-I (Electronic Length Frequency Analysis) module in FiSAT (FAO-ICLARM Stock Assessment Tools) was used for estimation of growth parameters (L∞, K). The total mortality was estimated following Pauly (ICLARM Fishbyte 2(1):9-13, Pauly 1983) whereas exploitation ratio and maximum sustainable yield were calculated following Gulland (1979). The asymptotic length (L∞) and growth coefficient (K) were estimated as 194 mm and 1.23 year−1, respectively. The species grows to 141.56 and 182.91 mm at the end of the 1st and 2nd years of life. The total natural and fishing mortalities were 6.63, 2.45 and 4.18 year−1 respectively. The value of growth performance index was 2.69. The exploitation ratio (E) was estimated as 0.63. As the exploitation ratio (E) is slightly beyond the optimum, there is likelihood of some threat of overexploitation. Though recruitment was continuous, major pulse was observed during April-May. The present investigation is a first report from Indian reservoir. The maximum sustainable yield of this species was estimated as 485.6 t against the present annual yield of 612.3 t. Avoiding overfishing and wise use of available resources are of prime importance for sustainable fishery management of the reservoir. [ABSTRACT FROM AUTHOR]

An ecosystem approach to fisheries management (EAFM) is as a new paradigm in fisheries management. In this study, a combination of geographic information systems (GISs) and multi-criteria decision-making method (MCDM) is proposed as a framework supporting an ecosystem approach to European sardine (Sardina pilchardus, Clupeidae) fishery management in Portugal. This case study was chosen due to the recent severe decline shown by the species. To develop an EAFM for the sardine fishery, a set of criteria were defined based on literature review and expert knowledge. To address multiple conflicting objectives, namely conservation and fisheries, five scenarios were considered: (i) baseline ; (ii) nurseries protection ; (iii) spawning areas protection ; (iv) fishery profit driven, and (v) safeguarding dependent fishing communities. Combination of GIS and MCDM methods highlighted important areas to implement spatial conservation measures for sardine. The analyses indicate that some areas are suitable for conservation in several scenarios, such as the area near Aveiro and the area near the Tejo estuary. However, conservation measures implemented in the area near Aveiro would imply higher economic trade-offs when compared with the actions applied in the region near the Tejo estuary. Results also suggested some of the conservation objectives, such as the protection of sardine eggs and juveniles, to not be compatible. The proposed framework is an important tool supporting EAFM by addressing conflicting objectives, trade-offs and identifying areas that could be considered as potential fishery closure sites or subjected to further analyses. [ABSTRACT FROM AUTHOR]

In this study, for the first time, we profile the actual protein sequences of known and potential allergens of premature hilsa shad (Tenualosa ilisha), an economically important fish of South Asian countries. Proteomics was employed to dissect the muscle tissue proteome collected from the riverine habitat hilsa samples. We successfully identified and quantified >600 proteins wherein many known allergens such as parvalbumins, beta-enolase, and creatine kinases were identified as abundant proteins in muscle tissue. Label-free quantitative proteomics revealed significant differences in the abundance of myosin, dynein, gamma-enolase, creatine kinase B-type, and collagens between the two hilsa samples. In silico analysis determined the allergen potential of these proteins. Notably, our findings indicate that many well-characterized allergen proteins are developmentally regulated in the muscle tissue. Thus, the profiling of a muscle tissue proteome map would further facilitate fundamental and applied research on hilsa fish and greatly improve our understanding of the crucial issue of hilsa customers' nutritional safety. [Display omitted] • First muscle tissue proteome map of Hilsa shad, an economically important fish. • Comparative allergome of immature Hilsa shad. • Actual peptide sequences of Hilsa allergen proteins were identified. • Some allergen proteins are developmentally regulated. [ABSTRACT FROM AUTHOR]

This study deals with the length‐weight relationships (LWRs) of three commercially important marine fishes belonging to the family Clupeidae from the major landing centers in Tuticorin, Mandapam, Thondi, Nagapattinam and Chennai in southeast coast of India. Monthly sampling were done at the respected landing centers from June, 2018 to April, 2019 from the commercial trawlers (with cod‐end mesh size of 25–35 mm) and gill netters (with different mesh size vary from 20 to 170 mm). The estimated 'b' values ranged from 3.1215 (Sardinella albella) to 3.1819 (Amblygaster clupeoides) and 'a' values varied from 0.0059 (A. clupeoides) to 0.0074 (S. albella). The study also provides a new maximum total length (TLmax) for two species A. clupeoides and Sardinella fimbriata. [ABSTRACT FROM AUTHOR]

Use of surrogacy remains a useful method for prioritizing research on representatives of at-risk groups of fishes, yet quantifiable evidence in support of its use is generally not available. Blade strike impact represents one of the most traumatic stressors experienced by fish during non-volitional movements through hydropower turbines. Here, we use data generated from laboratory trials on blade strike impact experiments to directly test use of surrogacy for salmonid and clupeid fishes. Results of logistic regression indicated that a -taxonomic (genus) variable was not a significant predictor of mortality among large rainbow trout and brook trout. Similar results were found for young-of-the-year shad species, but genus-level taxonomy was a significant predictor of mortality while species was not. Multivariate analysis of morphometric data showed that shad clustered together based on similarities in fish shape which was also closely associated with genus. Logistic regression including size as a major covariate suggested total fish length was not a significant predictor of mortality, yet dose−response data suggest differential susceptibility to lower strike velocities. We suggest that use of surrogacy among species is justifiable but should be avoided within a species since the effects of size remain unclear.

The mitochondrial genome of a blacktip sardinella, Sardinella melanura was determined by high-throughput sequencing (HTS) technique. The mitogenome of S. melanura (16,646 bp), encoded the canonical 37 mitochondrial structural genes (13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes). The gene arrangement of S. melanura was identical to its relative species including Sardinella lemuru, Sardinella longiceps and Sardinella gibbosa. Except for COX1 (GTG), all the other PCGs showed the typical ATG as start codon. Incomplete stop codons were identified in ND2, COX2, COX3, ND3, ND4, and Cytb. The phylogenetic tree result showed that S. melanura was most closely related to S. jussieu, S. lemuru, and Sardinella maderansis with 83% identity, respectively.