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Full-Text Articles in Physical Sciences and Mathematics
Life History, Population Dynamics And Yield-Per-Recruit Modeling Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Area, Luiz R. Barbieri
Life History, Population Dynamics And Yield-Per-Recruit Modeling Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Area, Luiz R. Barbieri
Dissertations, Theses, and Masters Projects
Otoliths, scales, dorsal spines, and pectoral fin rays, of Atlantic croaker, Micropogonias undulatus, were compared for legibility of presumed annuli and precision in repeated readings, to determine the best structure for ageing. Marks on transverse otolith sections were easiest to read and showed the best agreement between readings. Fish collected in Chesapeake Bay and in Virginia and North Carolina coastal waters during 1988-1991 were then aged using otolith sections. Ages 1-8 were recorded, but eight-year-old fish were rare. Marginal increment analysis showed that for ages 1-7 annuli are formed once a year during the period April-May. Otolith age readings were …
The Structure Of The Holocephalan Head And The Relationships Of The Chondrichthyes, Eileen D. Grogan
The Structure Of The Holocephalan Head And The Relationships Of The Chondrichthyes, Eileen D. Grogan
Dissertations, Theses, and Masters Projects
The interrelationship of the chondrichthyan subclasses is evaluated based on divergence in the nature of the suspensorium, the preorbital cranial anatomy, the distribution of major venous sinuses and localization of hematopoietic tissue. The anatomy of representative extant taxa was examined by radiography and/or dissection. Fossil selachians, paraselachians, and holocephalans of the Bear Gulch of Montana, U.S.A. (Mississippian, Namurian E2B) were studied for evidence of vascular pigmentation, suspensorium, and cranial, branchial, and pectoral anatomy. These studies validate the suspensorial condition of autodiastyly and suggest autodiastyly is a fundamental condition involved in the basic radiation of Chondrichthyes. The plesiomorphous condition of all …