8 resultados para PHYLOGENETIC SYSTEMATICS
em Aquatic Commons
Resumo:
This report owes its genesis to the foresight and enthusiam of Dr. Kazuhiro Mizue. By happy circumstance, Professor Mizue contacted me in 1983 with his visionary ideas on cooperative programs. He noted that the time was right because the Japan Society for the Promotion of Science and the National Science Foundation had mutually given priority to cooperative programs in marine biology. I therefore agreed to act as the U.S. coordinator and proposed to NSF, a short trip to Japan to negotiate site visits and timing with ten previously appointed Japanese scientists and, if that trip were successful, to negotiate a joint research project, possibly followed by a joint seminar. (PDF file contains 528 pages.)
Resumo:
For an explanation of the dynamics of numbers of chydorids, appearing a massive group in the littoral of fresh water bodies, the structure of the limbs of 29 species was studied.
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The morphology, increase and systematica of Sphaerotilus natans is studied and culture methods examined.
Resumo:
Evolutionary associations among the four North American species of menhadens (Brevoortia spp.) have not been thoroughly investigated. In the present study, classifications separating the four species into small-scaled and large-scaled groups were evaluated by using DNA data, and genetic associations within these groups were explored. Specifically, data from the nuclear genome (microsatellites) and the mitochondrial genome (mtDNA sequences) were used to elicit patterns of recent and historical evolutionary associations. Nuclear DNA data indicated limited contemporary gene flow among the species, and also indicated higher relatedness within the small-scaled and large-scaled menhadens than between these groups. Mitochondrial DNA sequences of the large-scaled menhadens indicated the presence of two ancestral lineages, one of which contained members of both species. This result may indicate genetic diver-gence (reproductive isolation) followed by secondary contact (hybridization) between these species. In contrast, a single ancestral lineage indicated incomplete genetic divergence between the small-scaled menhaden. These results are discussed in the context of the biology and demographics of each species.
Resumo:
Following the initial description of a species of Sebastes from the Atlantic in the late 1700’s, in the late 1800’s the incredible taxonomic diversity of the genus began to be recognized as more species were discovered in northeast Pacific waters. With over 100 species, most of them from the North Pacific, the genus Sebastes (rockfishes) now presents taxonomic problems at every level. For example, although early efforts to understand relationships among the species resulted in the erection of several subgenera, those and more recent efforts remain largely unsuccessful. Also, the position of the genus within the order Scorpaeniformes, as well as the limits of the genus and the validity of some species are all unresolved. This paper examines the worldwide history and status of taxonomic studies on Sebastes, and reviews the 23 subgenera that have been erected over the years. This review of research, which includes morphological and genetic studies, provides a framework against which to evaluate studies using new genetic techniques.
Resumo:
On an early fall day in September 1962 I sat quietly, thoughtfully, at my large desk in a newly renovated corner office in the old Crane wing of the Lillie Building, Marine Biological Laboratory (MBL), Woods Hole, Massachusetts. Looking out through high, ancient windows, I could see the busy main street of Woods Hole in the foreground, Martha's Vineyard beyond, behind me the MBL Stone Candle House, across the street the Woods Hole Oceanographic Institution (WHOI) and to the far right, the Biological Laboratory of the Bureau of Commercial Fisheries (BCF)(Fig. 1). Down the inner hall from my office stretched renovated quarters for the fledgling, ongoing, year-round MBL Systematics-Ecology Program (SEP), which I had been invited to direct.
Resumo:
The order Zoantharia (Zoanthids) is one of the most neglected orders of cnidarians in the Persian Gulf. The present study aims to investigate the biodiversity of this order with morphological and molecular examination in the Persian Gulf. For this purpose, 123 colonies of zoanthids with variety of shape and colors have been collected from intertidal and shallow water zone of four islands, i. e. Hengam, Qeshm, Larak and Hormoz. After sampling, morphological characteristics of each specimen were recorded based on in situ photographs. Then DNA was extracted using the cetyl trimethyl ammonium bromide (CTAB) method. Both mitochondrial 16S ribosomal DNA (mt 16S rDNA) and cytochrome oxidase subunit I (COI) gene fragments were amplified and sequenced. The results of preliminary morphological identification integrated with two mitochondrial markers sequencing demonstrated the presence of five different species in this region; Zoanthus sansibaricus, Palythoa mutuki, Palythoa cf. mutuki, Palythoa tuberculosa and Neozoanthus persicus?. Although at first sight, morphological properties were not successful to delineate zoanthid species, they become reliable criteria to identify and delineate species in field studies after molecular identification.