Decapterus Russelli Research Articles

Mitochondrial DNA analysis of the geographic structure of Indian scad mackerel in the Indo-Malay archipelago

Sequence analysis of a fragment of the cytochrome b gene in Decapterus russelli sampled from the Indo-Malay archipelago revealed two distinct mitochondrial clades (mean nucleotide divergence=2·2%) whose geographic distribution was heterogeneous (Nei's GST=0·416). This pointed to a complex pattern of genetic differentiation and demonstrated limited genetic exchange between populations in this highly mobile species.

Mitochondrial DNA analysis of the geographic structure of Indian scad mackerel in the Indo‐Malay archipelago

Sequence analysis of a fragment of the cytochrome b gene in Decapterus russelli sampled from the Indo‐Malay archipelago revealed two distinct mitochondrial clades (mean nucleotide divergence=2·2%) whose geographic distribution was heterogeneous (Nei's GST=0·416). This pointed to a complex pattern of genetic differentiation and demonstrated limited genetic exchange between populations in this highly mobile species.

Studies on the age, growth and mortality rates of Indian scad Decapterus russelli (Ruppell) from Mumbai waters

Investigations have been carried out on the age, growth and mortality of Decapterus russelli (Ruppell) based on the length frequency data. The asymptotic length ( L ∞) and growth coefficient ( K) were estimated as 240 mm and 1.42 yr −1, respectively. The species grows from 182 to 226 mm at the end of I and II years of life. The total, natural and fishing mortalities were 7.75, 2.63 and 5.12 yr −1, respectively. Munro’s phi prime was 2.91. The exploitation rate ( U) and exploitation ratio ( E) were 0.65 and 0.66, respectively. As the exploitation ratio ( E) is well beyond the optimum, there is every likelihood of some threat of stock depletion.

Capillary gas chromatography determination of aliphatic hydrocarbons in fish and water from Oman

Aliphatic hydrocarbon residues were monitored in two fish species, Indian mackerel (Rastrelliger Kanaguria) and Indian scad (Decapterus russelli) collected from local markets in three different cities in Oman. Residues were also monitored in water samples collected from two sites of the Gulf of Oman. Sampling was conducted twice, in July and again in February to have a thorough understanding of the dynamics of aliphatic hydrocarbon residues. Results indicated the presence of petrogenic aliphatic hydrocarbons ranging from C 12–C 28 in fish and water samples alike. Fish and water chromatograms were characterized by an unresolved complex mixture (UCM), a confirmatory sign of petrogenic origin of monitored hydrocarbons. Residue levels showed some variations related to sampling sites and time of sampling.

Residues of polycyclic aromatic hydrocarbons in fish and water from Sultanate of Oman

Concentrations of polycyclic aromatic hydrocarbons (PAH) were determined in the muscles and the skin of two fish species, Indian mackerel ( Rastrelliger kanagurta ) Indian scad ( Decaptens russelli ) and marine water collected from different places around the Sultanate of Oman, in February and July 1995. Pyrene was the most frequently detected compound with concentration ranging from 42.6 to 405.2 mug kg-1, while benzo(k)fluoranthene was the least frequently detected compound with concentrations ranging from 98.8 to 227.9 mug kg-1. Residues of PAH detected in fish samples have followed no particular pattern and were rather irregular. Concentrations of PAH detected in the two fish species are relatively higher than concentrations detected in seafood around the Gulf Area.

Mercury concentrations in ten fish species from the Arabian Sea, Pakistan

Mercury concentrations in ten fish species harvested from twenty sites in the South West Coast of Pakistan, are reported. The following fish, within a limited weight range, were included in this study: Picnic seabream, Indian scad, Indian ariomma, Bigeye scad, Threadfins, Cornet fish, Lefteye flounder, Gold band goatfish, Smooth dwarf monocle bream and Half‐mourning coraker. Comparative estimations were also made of mercury content in marine water from various sites. Statistical correlations based on the metal distribution were evolved on the basis of fish‐to‐site and fish‐to‐fish to provide evidence for the observed mercury concentrations in relation to sites and species. The minimum mercury concentration was encountered in Picnic seabream (X = 0.046 μg/g, wet weight) and the maximum concentration (X = 0.269 μg/g, wet weight) in Cornet fish. The present data were compared with the corresponding data on the concentrations of mercury in some common fish species in addition to prawn, crab and squid from the...