The center of mass and center of charge of the electron

9th Biennial Conference on Classical and Quantum Relativistic Dynamics of Particles and Fields (IARD)

Genetic variation of rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (S. borealis) inferred from allozymes

Rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (Sebastes borealis) were collected from the Washington coast, the Gulf of Alaska, the southern Bering Sea, and the eastern Kamchatka coast of Russia (areas encompassing most of their geographic distribution) for population genetic analyses. Using starch gel electrophoresis, we analyzed 1027 rougheye rockfish and 615 shortraker rockfish for variation at 29 proteincoding loci. No genetic heterogeneity was found among shortraker rockfish throughout the sampled regions, although shortraker in the Aleutian Islands region, captured at deeper depths, were found to be significantly smaller in size than the shortraker caught in shallower waters from Southeast Alaska. Genetic analysis of the rougheye rockfish revealed two evolutionary lineages that exist in sympatry with little or no gene f low between them. When analyzed as two distinct species, neither lineage exhibited heterogeneity among regions. Sebastes aleutianus seems to inhabit waters throughout the Gulf of Alaska and more southern waters, whereas S. sp. cf. aleutianus inhabits waters throughout the Gulf of Alaska, Aleutian Islands, and Asia. The distribution of the two rougheye rockfish lineages may be related to depth where they are sympatric. The paler color morph, S. aleutianus, is found more abundantly in shallower waters and the darker color morph, Sebastes sp. cf. aleutianus, inhabits deeper waters. Sebastes sp. cf. aleutianus, also exhibited a significantly higher prevalence of two parasites, N. robusta and T. trituba, than did Sebastes aleutianus, in the 2001 samples, indicating a possible difference in habitat and (or) resource use between the two lineages.

Biology and Potential Use of Pacific Grenadier, Coryphaenoides acrolepis, off California

Grenadiers (family Macrouridae) are the most abundant fish on most continental slope areas worldwide. Off California the Pacific grenadier, Coryphaenoides acrolepis, occurs in relatively large numbers and may have marketing potential. This repon provides information on the biology of the species and catch results from a number of scientific cruises. Catch data on several other species found together with Pacific grenadier, panicularly sablefish, Anoplopoma fimbria, are also given. The fish were caught with a bottom trawl (15 trawls), and with free-vehicle longline gear (117 sets). The latter was a hook and line system in which the gear was dropped to the seafloor untethered to the fishing vessel, and floated to the surface, with the catch, when detachable weights were automatically released. Sablefish dominated longline catches in depths of 200-600fm (334-1,098m), while Pacific grenadier was most abundant between 600 and 1,OOOfm (1,098-1,830m). Best trawl catches of Pacific grenadier were made at depths between 615 and 675fm (1,125 and 1,235 m) and at 760fm (1,391 m). Ripe females were absent from our samples, but spent females were found during the entire year with highest numbers in the spring and early summer. Only one larva was found despite extensive sampling with plankton nets. Pacific grenadier was found to have good edible qualities by a taste-test panel, although the protein content (15 percent) and flesh yield (24 percent) were significantly lower than those of other fishes. A second species, the giant grenadier, Albatrossia pectoralis, was found to have exceptionally poor eating qualities and even lower protein content.

Body shape variation and colour change during growth in a protogynous fish

Protogynous sequential hermaphroditism is very common in marine fish. Despite a large number of studies on various aspects of sequential hermaphroditism in fish, the relationship between body shape and colour during growth in dichromatic species has not been assessed. Using geometric morphometrics, the present study explores the relationship between growth, body shape and colouration in Coris julis (L. 1758), a small protogynous labrid species with distinct colour phases. Results show that body shape change during growth is independent of change in colour phase, a result which can be explained by the biology of the species and by the social control of sex change. Also, during growth the body grows deeper and the head has a steeper profile. It is hypothesized that a deeper body and a steeper profile might have a function in agonistic interactions between terminal phase males and that the marked chromatic difference between colour phases allows the lack of strict interdependence of body shape and colour during growth.