Molecular Phylogeny Of The Sciaenidae In China

Sciaenid fishes (Osterichthyes : Percitormes: Sciaenidae) inhabit in the shallowcoastal waters of tropical and subtropical seas with the bottom composed of sand ormuddy sand and rivers emptying freshwater. Except few widely distributed speices,mostly sciaenid fishes are endemic. Sciaenid fishes are of highly commercial value, forexample, Both Pseudosciaena crocea and Pse. polyactis were listed as so-called"Traditional Chinese Four marine Fishery". And, many of which are important breedingfishes. Due to their special ecological habits, sciaenid fishes are prone to be overfished,many species are now listed as endangered. Sciaenid fishes are so extensive anddiverse that the family comprises more than 70 gene and 300 species. The classificationof the Sciaenid fishes is based mainly on comparative anatomy of theswimming-bladders and otolithes, and some morphormetric characters, however, manysciaenid fishes are so closely related that it is very difficult define them, andclassification of the Sciaenid fishes remain very controversial. Therefore, a molecularphylogenetic surveys of Sciaenid fishes would be higly desirable to deduce relationshipsof various Sciaenid fishes, improving the selection of breeding of cultural strains andthe design of conservation strategies.DNA sequence analysis is the method of choice in phylogenetic reconstruction.Almost several molecular phylogeny have been done on Sciaenidae, few taxon wereinvolved in those studies. In the present study, Sequences of parial mtDNA 16S rRNAgene of 16 species 10 genus of Sciaenid fishes in the coastal waters of china weredetermined. Combined with available homologous sequences of the Sciaenid fishe fromGenBank, mtDNA sequences of 37 species 22 genus of Sciaenid fishes were used toreconstruct molecular phylogeny using Neiber-Joining, Molecualr evolution, MaximumPasimony and Maximum likelihood methods. Phylogenetic relationships with emphasis onChinese species were addressed as follows:1. Johniinae, including Johnius and Wak, were distantly related to other Sciaenidfishes, which were consistent with morphological classification. The genetic distanceamong Johnius species was beyond those among other intrageneric species in the family,suggesting that Johnius species were differentiated long. 2. Argyrosominae are polyphyletic, as Nibea didn't clustered withArgyrosomus(=Pennahia). Although Pennahia argentata are placed adjacent toPennahia anea,their genetic distance is relative large, suggesting that the monophyly ofthe genus remains to be tested. Nibea albiflora is sister to Nibea coibor, which didn'tclustered with Nibea miichtheoides(=Argyrosomus amoyensis) and Nibea discanthus(=Protonibea diaeanthus). Protonibea diacanthus clustered with Chrysochir Trewavas,and Argyrosomus amoyensis was close to Sciaenops ocellatus, Atractoscion nobilis,Cynoscion regalis, supporting the separation of these two species from Nibea.Obvious geographic differentiation were observed in Nibea coibor and Pennahiaargentata.3. Otolithinae is not monophyletic, as Chrysochir aureu clustered with Protonibeadiacanthus, instead of Otolithes. Otoiithes might be monophyletic. O. argenteus andO.rubber was so closely realated that they might be conspecies.4. Pseudosciaenidea and Collichtys were so closely related that genetic distanceamong them were equal, is not smaller than those among other intergenic species, andspecies of them were interwined with each other, suggesting the possibility that theymight be merged to one genus. Miichthys were placed adjacent to Pseudosciaenidea-Collichtys clade with low bootstrap value, indicating that the monophyly ofPseudosciaeninae deserve to be further studied.5. Dendrophysa russelii didn't clustered with Umbrina Cuvier and Sciaena russelli,and were isolated to the rest of Sciaenid fishes, its evolutionary position is elusive.Primary molecular phylogenetic surveys of mtDNA sequences in Sciaenid fishesindicated great difficulties existed at various rank of taxonomic treatment of Sciaenidfishes. Extensive sampling and intensive studies are needed to work out phylogeny ofSciaenidae.