Sea Bass Species Research Articles

Establishment and characterization of a novel cell line derived from spotted sea bass Lateolabrax maculatus and its susceptibilities to iridoviruses

The spotted sea bass (Lateolabrax maculatus), which holds significant commercial value, is extensively cultivated in China, Japan, and Southeast Asian countries. This study reports the establishment and characterization of a novel continuous cell line, designated as LMK cells, derived from the kidney tissue of spotted sea bass, The LMK cell line, primarily composed of epithelial-like cells, has been successfully subcultured in Medium 199 supplemented with 10 % fetal bovine serum (FBS) for over 60 passages. Mitochondrial genome sequencing and cytochrome c oxidase subunit I gene amplification verified the origin of the LMK cells from L. maculatus, distinguishing them from L. japonicus. Optimal culture conditions for LMK cells at passage 35 were determined to be 10 % FBS at 27 °C. Chromosomal analysis indicated that the cell line possesses 48 chromosomes. To assess viral susceptibility, LMK cells were exposed to the red sea bream iridovirus and largemouth bass ranavirus. Both iridoviruses induced cytopathic effects within 3 days post-infection and triggered immune-related gene responses. This study demonstrates that the LMK cell line is a valuable resource for molecular, virological, and immunological research in L.maculatus and other sea bass species.

Chromosome-level genome assembly for the largemouth bass Micropterus salmoides provides insights into adaptation to fresh and brackish water.

Largemouth bass (LMB; Micropterus salmoides) has been an economically important fish in North America, Europe, and China. This study obtained a chromosome-level genome assembly of LMB using PacBio and Hi-C sequencing. The final assembled genome is 964Mb, with contig N50 and scaffold N50 values of 1.23Mb and 36.48Mb, respectively. Combining with RNA sequencing data, we annotated a total of 23,701 genes. Chromosomal assembly and syntenic analysis proved that, unlike most Perciformes with the popular haploid chromosome number of 24, LMB has only 23 chromosomes (Chr), among which the Chr1 seems to be resulted from a chromosomal fusion event. LMB is phylogenetically closely related to European seabass and spotted seabass, diverging 64.1 million years ago (mya) from the two seabass species. Eight gene families comprising 294 genes associated with ionic regulation were identified through positive selection, transcriptome and genome comparisons. These genes involved in iron facilitated diffusion (such as claudin, aquaporins, sodium channel protein and so on) and others related to ion active transport (such as sodium/potassium-transporting ATPase and sodium/calcium exchanger). The claudin gene family, which is critical for regulating cell tight junctions and osmotic homeostasis, showed a significant expansion in LMB with 27 family members and 68 copies for salinity adaptation. In summary, we reported the first high-quality LMB genome, and provided insights into the molecular mechanisms of LMB adaptation to fresh and brackish water. The chromosome-level LMB genome will also be a valuable genomic resource for in-depth biological and evolutionary studies, germplasm conservation and genetic breeding of LMB.

Habitat use of five key species of reef fish in rocky reef systems of southern Brazil: evidences of MPA effectiveness

Species functional behaviors amidst the food web, such as feeding ecology in ecosystems, are directly connected to their habitat preferences and use. In reef ecosystems, groupers and sea bass are considered key species, as top-down controllers, regulating the trophic levels on which they feed. Moreover, they are a diversified group of actinopterygian fishes, ranging from 7 to 250 cm of total length and inhabiting many types of reef habitats, from shallow waters up to 200 m deep. Due to the exceptional ecological and commercial importance of groupers and sea bass to the rocky reef systems of southwestern Atlantic and considering the small amount of information on their behavior and habitat use available for this particular region, three questions have emerged. First, how are the species spatially distributed considering the topography complexity of their environment? Second, do large Epinephelids and small Serranids have the same use of the water column, when foraging (e.g., position related to the substrate)? Third, do marine protected areas influence the distributional patterns of both families? To answer these questions, we assessed the spatial distribution and habitat use of two dominant species of groupers (Epinephelus marginatus, Mycteroperca acutirostris) and three species of sea bass (Diplectrum radiale and Serranus flaviventris and S. baldwini), using underwater visual census at Santa Catarina State, southern Brazil, during the austral summers of 2010 and 2011. All of the five sympatric species studied are directly associated with specific topographic characteristics that may be related to shelter as well as to reproduction and feeding. Except for M. acutirostris, which was mainly recorded foraging in the water column, all the remaining species are benthic dwellers. Significant evidences of effectiveness advocate that Arvoredo Marine Biological Reserve has critical importance as a refuge for heavily targeted reef species in southern Brazil, such as E. marginatus and M. acutirostris. The establishment of more protected marine areas that encompass the nursery areas near AR, along with proper enforcement, is critical to the protection of endangered and vulnerable marine species. The present work has contributed to the knowledge of habitat use and partitioning of some key reef fishes, especially target species, which is critical to effective conservation measures, including the design and management of MPAs.

Connectivity across the Caribbean Sea: DNA barcoding and morphology unite an enigmatic fish larva from the Florida straits with a new species of sea bass from deep reefs off Curaçao.

Integrative taxonomy, in which multiple disciplines are combined to address questions related to biological species diversity, is a valuable tool for identifying pelagic marine fish larvae and recognizing the existence of new fish species. Here we combine data from DNA barcoding, comparative morphology, and analysis of color patterns to identify an unusual fish larva from the Florida Straits and demonstrate that it is the pelagic larval phase of a previously undescribed species of Liopropoma sea bass from deep reefs off Curaçao, southern Caribbean. The larva is unique among larvae of the teleost family Serranidae, Tribe Liopropomini, in having seven elongate dorsal-fin spines. Adults of the new species are similar to the golden bass, Liopropoma aberrans, with which they have been confused, but they are distinct genetically and morphologically. The new species differs from all other western Atlantic liopropomins in having IX, 11 dorsal-fin rays and in having a unique color pattern–most notably the predominance of yellow pigment on the dorsal portion of the trunk, a pale to white body ventrally, and yellow spots scattered across both the dorsal and ventral portions of the trunk. Exploration of deep reefs to 300 m using a manned submersible off Curaçao is resulting in the discovery of numerous new fish species, improving our genetic databases, and greatly enhancing our understanding of deep-reef fish diversity in the southern Caribbean. Oh the mother and child reunion is only a moment away. Paul Simon.

Description of two new species of sea bass (Teleostei: Latidae: Lates) from Myanmar and Sri Lanka

Description of two new species of sea bass (Teleostei: Latidae: Lates) from Myanmar and Sri Lanka

Description of two new species of sea bass (Teleostei: Latidae: Lates) from Myanmar and Sri Lanka

Two new species of Lates Cuvier are described. Lates lakdiva, new species, from western Sri Lanka, differs from its Indo-Pacific congeners by its lesser body depth, 26.6‒27.6% SL; 5 rows of scales in transverse line between base of third dorsal-fin spine and lateral line; 31‒34 serrae on the posterior edge of the preoperculum; third anal-fin spine longer than second;47‒52 lateral-line scales on body; and greatest depth of maxilla less than eye diameter. Lates uwisara, new species, fromeastern Myanmar, is distinguished by possessing 7 scales in transverse line between base of third dorsal-fin spine and lat-eral line; eye diameter 4.4‒4.7% SL; body depth 28.4‒34.5% SL; and third anal-fin spine shorter than the second. Despitesubstantial genetic variation, L. calcarifer sensu lato is widely distributed, from tropical Australia through Indonesia, Sin-gapore and Thailand, westwards to at least the west coast of India. Caution is urged in translocating Lates in the Indo-Pacific region as other yet unrecognized species likely exist. The status of the type specimens of L. calcarifer is discussed,and a common lectotype designated for L. heptadactylus and L. nobilis. While Lates vacti (type locality Bengal) may bea valid species, L. cavifrons and L. darwiniensis are considered synonyms of L. calcarifer. Plectopomus Goldfuss and Ptertopomus Goldfuss are shown to be incorrect subsequent spellings of Plectropomus Oken.

Reproductive Strategies of Sea Basses based on Larval Abundance in Magdalena Bay, Mexico, 1982–1986

AbstractWe analyzed the reproductive strategies of four sea basses Paralabrax spp. based on larval abundance and sea surface temperature during a period affected by the El Niño of 1982–1983. Zooplankton samples were taken monthly in the Magdalena–Almejas lagoon complex of Baja California Sur, Mexico, from January 1982 to November 1986. Larvae of four sea bass species were recorded; those of the spotted sand bass P. maculatofasciatus were dominant, contributing 43% of total abundance. Barred sand bass P. nebulifer constituted 28% of the sampled larvae, goldspotted sand bass P. auroguttatus contributed 26%, and kelp bass P. clathratus made up 3%. During 1983–1984, the larval abundances of spotted sand bass and goldspotted sand bass decreased (by >50% and 90%, respectively), while the abundance of barred sand bass increased by nearly 25%. A seasonal larval abundance maximum for all species was recorded in summer and autumn, but a differential reproductive pattern inferred from larval abundance was determined. Spotted sand bass showed continuous reproductive activity with peaks in February, June, August–September, and November. Barred sand bass larval abundance indicated one reproductive period with peaks in June and November; a single reproductive period (August) was found for goldspotted sand bass. The abundance of kelp bass larvae was very low, and we were not able to identify a reproductive pattern. Spawning habitat occurred at the relatively narrow temperature range of 19–24°C for spotted sand bass and at 24–28°C for barred sand bass; the widest range was recorded for goldspotted sand bass (22–29°C). The temporal segregation and the differences in spawning habitat permitted the identification of three different reproductive strategies in which there exists a certain degree of overlap. This study represents a first step in understanding the reproductive cycle of three species of sea basses in Magdalena Bay.

High permissivity of the fish cell line SSN-1 for piscine nodaviruses.

Seventeen isolates of piscine nodavirus from larvae or juveniles of 13 marine fish species affected with viral nervous necrosis (VNN) were examined for their infectivity to a fish cell line SSN-1. Based on cytopathic effects (CPE) and virus antigen detection by fluorescent antibody technique (FAT) after incubation at 25 degrees C, the infectivity of these virus isolates was divided into 4 groups. Group 1, including 9 virus isolates from 4 species of grouper, 2 species of sea bass, barramundi, rock porgy, and Japanese flounder showed CPE characterized by rounded, granular cells with heavy cytoplasmic vacuoles within 3 d post-incubation (p.i.), and the monolayer partially or completely disintegrated over 3 to 6 d p.i. Scattered FAT-positive cells appeared at 3 h p.i. and spread through the cell sheet with an increasing fluorescence signal over 24 h p.i. Group 2, consisting of 3 virus isolates from striped jack, induced CPE with thin or rounded, granular, refractile cells without conspicuous vacuole formation, and extensive FAT-positive reaction was observed in a time course similar to that of Group 1. Cells inoculated with Group 3 (1 isolate from tiger puffer) developed no distinct CPE but viral infection was evidenced by localized FAT-positive cells. There were no FAT-positive cells in Group 4, which included 4 isolates from Japanese flounder, Pacific cod and Atlantic halibut. However, when incubation was performed at 20 degrees C, the SSN-1 cells inoculated with the Group 3 isolate showed CPE similar to that of Group 1 and extensive FAT-positive reaction. Evidence of virus proliferation at 20 degrees C was also obtained in Group 4 isolates. The virus titers in the infected fish varied from 10(11) to 10(16) tissue culture infectious dose (TCID50) g(-1) of fish. There is a good correlation between these infectivities to the SSN-1 cells and the coat protein gene genotypes of the isolates. The present results indicate that SSN-1 cells are useful for propagating and differentiating genotypic variants of piscine nodavirus.