Marine Fish Research Articles

ABSTRACTEstuarine lagoons provide nursery habitats for marine fishes; however, small lagoons (< 1 km2) have been overlooked. To evaluate the nursery function of small estuarine lagoons (SELs) for temperate marine fish, this study used seining on the coast of the northwestern Pacific (Kyushu, temperate Japan) during the juvenile seasons (winter and spring) to perform juvenile sampling at two scales and an abundance/size comparison of blackfin seabass (Lateolabrax latus). As a preliminary survey, habitat‐scale (inside vs. outside lagoon habitats) sampling was attempted in two SELs during February and April. Subsequently, seascape‐scale sampling was undertaken during the juvenile season (January–May). The seascape consisted of two types of estuaries (lagoons and rivers) and sandy beaches (embayed and exposed). A preliminary survey showed no clear difference in abundance among the habitats, but significantly larger juveniles were observed inside than outside the two SELs. In the seascape survey, peak juvenile abundance during the first half of the study period was concentrated in habitats other than the lagoon estuary, whereas no peak was recorded during the second half. Moreover, the lagoon estuary was significantly larger than the marine habitats, and the monthly occurrence of juveniles was continuous in the lagoon estuary but intermittent in the riverine estuary. These results imply that seabass juveniles utilize the SEL habitat as they grow, highlighting the potential nursery function of estuarine lagoons for marine fish, even at a small scale.

Development and evaluation of recombinant multi-epitopes vaccine against nervous necrosis virus.

Medium optimization of three marine probiotics and their application in the culture of Sebastes schlegelii.

Oxidative stress, inflammation, and apoptosis contribute to the pathogenesis of Amyloodinium ocellatum infection in yellowfin seabream (Acanthopagrus latus).

Arsenic speciation in freshwater fish using high performance liquid chromatography and inductively coupled plasma mass spectrometry.

The study was aimed to analyse the marketing channels, intermediary involvement, their roles in fish marketing, and associated costs throughout the movement of fish in Bagerhat, Bangladesh. Specifically, the investigation focused on the marketing channels and value chain of commercially significant marine fish, particularly sea bass (Lates calcarifer), in Bagerhat area. Questionnaire survey method was used for the data collection and relevant information of this research. It was observed that intermediaries collectively yield significant profits, resulting in higher fish prices in the consumer market. The marketing margin for sea bass was calculated at 26%, with fishermen receiving 74%, 80%, and 90% of the consumer purchase price in the primary, secondary, and retail markets, respectively. In the local sea bass market, five intermediaries were involved (sea bass farmer, aratdar, wholesaler, retailer, and consumers), while in distant markets included four intermediaries in total marketing channel (sea bass farmer, wholesalers, retailers, and consumers). The major challenges in the marketing channel are inadequate infrastructure, transportation amenities, and a significant number of intermediaries for the commercially important marine fishes. To establish a sustainable fish marketing system, requires the organizational support, government assistance, extension services, and training opportunities for market operators. J. Sylhet Agril. Univ. 11(1): 01-08, 2024

Geographic and ecological drivers of contaminants and nutrients in commercial fish species.

Morphological, histopathological, and phylogenetic insights on a new calyptospora species that causes hepatic coccidiosis in a fish from the Brazilian amazon.

Arsenic species in coastal marine fish species from the Southwest Atlantic Ocean: Human health risk implications.

Abstract Marine protected areas (MPAs) have been increasingly developed to protect fish communities and restore their ecological services. Shallow water fish populations may also find a natural refuge in the depths of the mesophotic reefs to escape overfishing and climate change. While a lot of knowledge has been acquired in the last decades about the effect of MPAs and, more recently, about mesophotic ecosystems, thanks to advances in monitoring methods, little is known about the effect of the interaction between protection and depth. Using environmental DNA metabarcoding, we sampled rocky fish assemblages of the Cap Roux no‐take marine reserve and the surrounding fished areas, covering several depth strata ranging from the surface to mesophotic depths. We found that protection, depth, and their interaction had a significant effect on fish diversity and assemblage composition. The vast majority of the 66 fish taxa identified in this study were detected inside the MPA. On the other hand, depth had a negative impact, with mesophotic reefs harboring the lowest diversity. Shallow protected locations were composed of rich fish assemblages, including targeted and threatened species that were rarely detected or even undetected outside the MPA and/or at mesophotic depths. In this study, depth does not seem to act as an efficient refuge for shallow communities. We suggest that the only effective protection comes from the MPA, highlighting the importance of these management tools for the long‐term conservation of fish populations.

Insights into the potential enhanced cadmium toxicity in marine fish Centroprostis striata in the context of global warming.

The present study aimed to monitor heavy metal concentrations in commonly consumed fishes, Mudskipper (Boleophthalmus boddarti) and Mullet (Mugil cephalus) from Panvel Creek, District Raigad, Maharashtra, West Coast of India using the US-EPA Method and analysis by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP- AES). Concentrations of Cadmium (Cd), Copper (Cu), Lead (Pb), Mercury (Hg), Nickel (Ni), and Zinc (Zn). It is reported that the extent of metal concentrations in muscle, gills, and liver tissue of fishes is varied considerably. In mudskipper, the hierarchy of the metals can be ranked as: Hg > Cu > Ni > Zn > Pb > Cd; whereas in mullet, it is in the order of Hg > Zn > Cu > Ni > Pb > Cd. Exceptionally high levels of heavy metals were observed in mullet and are attributed to the habitat and feeding behavior of this species. Comparatively, lower levels of metals are recorded in mudskippers and may be due to the diet, feeding habits and migration routes. The coastal communities along the Panvel creek are dependent on unprocessed marine fish. Therefore, consumption of contaminated marine food is the major route of human exposure to toxic elements. This study recommends the periodic monitoring of coastal water, sediment, and marine biota for the extent of bioaccumulation of metals. Further, the findings of the present work should be used as baseline data for future assessment of metal pollution in the marine biota from Panvel creek and also for the better management of the coastal ecosystem and the safety of human beings.

Ecotoxicological impact of the fungicide tebuconazole on fish: a historical review, global trends and challenges.

ABSTRACTEffective sample collection is a pivotal step in environmental DNA (eDNA) workflows. For aquatic eDNA applications, this typically requires water filtration and cold storage, which present logistical challenges in remote or resource‐limited settings. Metal–organic frameworks (MOFs) are porous materials composed of metal ions coordinated with organic linkers that can form around biological molecules in solution. By directly encapsulating and preserving eDNA in situ within a collected water sample, MOFs may simplify field sampling without the need for specialized equipment. In this study, eDNA capture and preservation from seawater samples using the MOF Zeolitic Imidazolate Framework‐8 (ZIF‐8) was compared with the performance of conventional filtration through mixed cellulose ester (MCE) filters. ZIF‐8 samples were stored at ambient temperature for 2 weeks, while MCE filters were either frozen or preserved in a lysis buffer for 5 days. The performance of each method was assessed by high‐throughput DNA sequencing and a metabarcoding assay targeting the 16S rRNA gene of fish. The MCE filter method detected, at present, a greater number of fish amplicon sequence variants (ASVs) and taxa than our trial application of the MOF method. However, community composition analyses (PERMANOVA and NMDS ordination) revealed no significant differences between the methods, demonstrating that despite yielding lower DNA quantities, ZIF‐8 collection effectively replicates the marine fish community structure. Analysis of taxon abundance showed that MOFs captured dominant taxa effectively but were less sensitive to rarer taxa. With further optimisation to enhance eDNA capture efficiency by MOFs beyond this trial application, MOFs could serve as a practical, field‐friendly alternative for eDNA sampling, especially where filtration is difficult.

Urogenital cannulation is a traditional method used in aquaculture to achieve sexual differentiation, but it is considered invasive. Ultrasonography is a valuable non-invasive tool for determining sex and gonadal development in fish species like mullet (Mugil liza) and Brazilian sardine (Sardinella brasiliensis) that lack sexual dimorphism. The methodology involves emitting high-frequency sound waves (20 MHz to 20,000 MHz) above the human hearing range. These waves interact with the tissues of the body, producing echoes that are detected by a transducer. The echoes are then processed by computer graphics to generate detailed images of the internal structures of the organism. This allows for the determination of the sex of fish based on the sonographic features of the tissues. For instance, in male fish, hypoechogenic structures reflect fewer sound waves, leading to darker images. Conversely, in female fish, hyperechogenic tissues reflect more sound waves, resulting in lighter images. It is possible to classify the gonadal maturation stage based on differences in image texture. This non-invasive method eliminates the need for specimen dissection. It is especially valuable when the goal is to preserve the spawners’ life and integrity. This review emphasizes the application of this technology in aquaculture, specifically targeting fish from the Clupeidae and Mugilidae families.

Identification, characterization, and functional verification of a novel fish-egg lectin (FEL) from the golden pompano, Trachinotus ovatus.

Microplastic occurrence in 21 coastal marine fish species from fishing communities on Viti Levu, Fiji.

Rapidly warming oceans temperatures and the occurrence of marine heatwaves are increasing at unprecedented rates and is further expected to increase the vulnerability of the already extreme marine environment of the relatively shallow Arabian Gulf to climate change impacts. The region's marine ecosystems are under ever-increasing pressures due to activities associated with the rapid urban development, making the Arabian Gulf one of the highest anthropogenically impacted regions in the world. Winters have shortened and temperatures have risen significantly over the last 24 years. In the channel waters of Abu Al Abyad Island, part of the southern Arabian Gulf, the average low winter sea surface temperature (SST) in January/February of 16.71 ± 0.9°C recorded during the years 2001-2004 increased to18.28 ± 0.7°C (an increase of 1.57°C) during the same period in 2020-2024. Similarly, the average high summer (July/August) SST of 34.75+0.4°C recorded in the years 2001-2004 increased to 36.04±0.7°C (an increase of 1.3°C) during the same period in 2020-2024. At the Aquaculture and Marine Studies Center (AMSC), Abu Al Abyad Island, Abu Dhabi, spawning data for Goldlined seabream (Rhabdosargus sarba), Silver black porgy (Sparidentex hasta) and White-spotted rabbitfish (Siganus canaliculatus), recorded during these years, showed a significant declining trend (P<0.05) in the duration of the spawning window relative to the optimal thermal regime for spawning of each species. Adoption of advanced technologies like climate controlled Recirculatory Aquaculture Systems (RAS) and selective breeding is recommended for the brood stock managers, to counter the negative effects of climate change.

The large yellow croaker (Larimichthys crocea) is one of China’s most economically important marine fish species, with its cage culture production leading the nation for many years. However, the rapid expansion of aquaculture has brought challenges such as germplasm degradation, reduced disease resistance, inconsistent product quality, and low adoption of improved strains, which have hindered the sustainable development of the industry. The primary objective of this review is to summarize the current practices and challenges in seedling selection for L. crocea. The secondary objectives include discussing the influence of genetic, physiological, and environmental factors on growth performance and proposing future research directions for sustainable breeding programs. This review covers key topics including morphological screening, growth performance evaluation, genetic diversity conservation, disease resistance improvement, and adaptation to environmental stress. It also explores the application of modern technologies such as marker-assisted selection, intelligent monitoring, environmental control, precision feeding, and disease prevention. Moreover, it highlights core issues in current breeding practices, such as over-reliance on single-trait selection and insufficient integration of environmental adaptability and disease resistance. Finally, future trends are discussed, emphasizing the integration of genomic tools with artificial intelligence to promote intelligent, precise, and sustainable breeding approaches. These insights aim to enhance aquaculture productivity while supporting long-term ecological balance and industry sustainability.

ABSTRACT The National Fish Habitat Partnership (NFHP) is a science based, non-regulatory, partnership-driven effort to conserve fish habitat across the USA. The NFHP was developed in the early to mid-2000s in response to the noted declines to fish populations and their associated habitats across the USA with the effort led by the Association of Fish and Wildlife Agencies and supported by a wide range of federal and state fisheries agencies along with conservation organizations. Since 2006, 20 Fish Habitat Partnerships have been organized around specific habitats, fish species, or geographic areas. These partnerships have implemented 1,613 projects resulting in 9,720 habitat enhancements or parcels of habitat protected, including 7,962 riverine or coastline miles and 98,255 acres of marine, lake, impoundment, and reservoir fish habitat along with 1,499 science and data products using US$60,613,842 of direct NFHP investment matched or leveraged by $332,841,072. The NFHP was codified by the U.S. Congress in 2020 and reauthorized in 2024, building on the strong initial foundation and ensuring success into the future. Follow-up publications to this overview paper are planned by each Fish Habitat Partnership to fully describe the depth and breadth of this key U.S. habitat program.