No description available.

No description available.

No description available.

No description available.

The marine fish family Ephippidae comprises eight genera and 15 species of extant fishes. Spadefishes or batfishes inhabit nearshore tropical to temperate waters. They are almost circumglobal in distribution, with the highest diversity in the Indo-west Pacific and the lowest diversity in the east Pacific and west Atlantic. Fifty-nine potentially informative morphological characters, 10 outgroup taxa, and eight ingroup taxa (i.e., genera) were used to explore sister group hypotheses to the Ephippidae, as well as generate a phylogeny of the Ephippidae. Seven constraint tree analyses were utilized to examine various sister group hypotheses based on previous morphological and molecular analyses by other researchers. These analyses resulted in maximally parsimonious trees ranging from 184 to 197 steps. as in previous analyses, both the suborder Acanthuroidei and the family Ephippidae were found to be monophyletic. Similar to the results from previous molecular and total evidence analyses, the exact placement of Scatophagidae within the Acanthuroidei could not be determined with this data set. However, in contrast to those results, Drepaneidae was found not to be the sister taxon to Scatophagidae. A single most-parsimonious tree of 187 steps (CI = 0.412) was chosen as the best hypothesis of relationships utilizing all taxa. However, few additional steps are needed to produce very different topologies. The phylogeny of the Ephippidae was invariant for all constraint tree analyses. Homoplask evolution is prevalent within the family (CI = 0.687; Bremer Total Support Index = 0.22). The phylogenetic hypothesis depicts two distinct clades: (Chastodipterus (Ephippus (Tripterodon ( Platax, Zabidius)))) + (Proteracanthus (Parapsettus, Rhinoprenes)). One new synapomorphy is proposed for the Ephippidae: posterior processes of the pelvic-fin girdle elongate, pointed, separate from one another, and parallel to the long axis of the body. Another new synapomorphy, the possession of an elongate fourth pharyngobranchial that completely overlays the dorsal surface of the upper toothplate of the fourth branchial arch, is homoplastically shared with Zanclidae. Ancestral area analysis determined that the ancestor to the Ephippidae most likely had an east Indian/west Pacific distribution. Omnivory is plesiomorphic within the Ephippidae and confirmed to be plesiomorphic for the Acanthuroidei.

Molecular markers and techniques were employed to develop a genetic key for the forensic identification of 16 species of Chesapeake Bay sportfishes and to investigate the stock structure of one of those species, the weakfish Cynoscion regalis. Regions within the ATP synthetase 6 (ATPase 6), Cytochrome b , cytochrome c oxidase I, NADH dehydrogenase 4 (ND4), and 12S/16S ribosomal RNA mitochondrial genes were amplified using the polymerase chain reaction (PCR) and digested with a bank of restriction endonucleases to find a genetic marker that exhibited complete interspecific differentiation and low intraspecific variation. Complete separation of all sixteen species was accomplished by restriction fragment length polymorphism (RFLP) analysis of an approximately 1495 bp region of the 12S/16S ribosomal RNA mitochondrial genes with the single endonuclease Rsa I. Ten species exhibiting a single digestion pattern and the remaining six were dimorphic. Analyses of four microsatellite loci and two nuclear intron regions were used to investigate the genetic basis of population structure of weakfish collected at five locations along the U.S. East Coast. Microsatellite mean expected heterozygosities ranged from a low of 8.5% for the SOCO14 marker to a high of 92.8% for the CNE612 locus. Mean expected heterozygosities for the CRESIA1 and RP2 intron regions were 5.1% and 24.0%, respectively. None of the sample genotype distributions differed significantly from Hardy-Weinberg expectations, and pairwise FST values were consistently low (0.000--0.087 for microsatellite loci, 0.000--0.050 for intron regions). Analyses of molecular variance (AMOVA) and exact F permutation tests of sample heterogeneity were nonsignificant for all loci. Evaluation of some individuals in the Georgia 1997 sample exhibiting unusually small allele sizes using the previously developed genetic key based on the 12S/16S rRNA marker revealed that two other species of Cynoscion , the sand seatrout C. arenarius and the silver seatrout C. nothus, had been inadvertently included in the sample of YOY weakfish. Based on data from the mitochondrial marker and the SOC050 microsatellite locus, a number of the Georgia 1997 fish were identified as hybrid offspring of weakfish and sand seatrout crosses.

No description available.

No description available.

No description available.

No description available.