Seasonal changes in the reproductive condition and body composition of free-ranging red drum, Scianops ocellatus.

Abstract Ž . Ž . Adult red drum Sciaenops ocellatus from a wild, autumn fall spawning population were studied over a 1-year period to evaluate seasonal changes in body composition in comparison with cultured red drum. Each month, female and male fish were captured and blood sampled. Standard Ž . length and weight were measured, and gonads, liver, intraperitoneal fat IPF , and a sample of Ž . muscle tissue were collected from each fish. Gonadosomatic index GSI , hepatosomatic index Ž . HSI , IPF ratio, protein and lipid composition of muscle and liver tissues, and lipid class composition of liver samples were determined for each fish. All tissue indices exhibited a similar Ž . seasonal cycle in both sexes, with highest HSI in spring March-April and maximal IPF ratio in May, followed in September and October by minimal values for HSI and IPF ratio. Whereas GSI was low, gonadal histology demonstrated activation of spermatogenesis and oocyte development in July and August. Liver composition varied dramatically throughout the year. Liver lipid content Ž . ranged from 7.4% of wet weight in November to 30.2% in August, with triglycerides TG being the most abundant component at all times. Liver protein was more stable, ranging from 11.5% in August to 16.3% in September. Muscle composition was relatively constant, with muscle crude protein ranging from 20.5% to 25.6% of wet weight and muscle lipid ranging from 0.4% to 2.2% R. Craig et al.r Aquaculture 190 2000 89-102 90 of wet weight. These data indicate that red drum utilize the liver as a major depot for lipid. Depletion of maximal lipid reserves from liver and IPF in late summer indicates that lipid stored during active spring and summer feeding supplies energy for reproduction which is mobilized Ž . rapidly within 1 month in this fall-spawning species. Body composition of wild fish is similar to that of laboratory cultured red drum.

Simultaneous measurement of the average ion-induced electron emission yield and the mean charge for isotachic ions in carbon foils

Article discussing the simultaneous measurement of the average ion-induced electron emission yield and the mean charge for isotachic ions in carbon foils

Experimental evidence for a discrete transition to channeling for 1.0-MeV protons in Si〈100〉

This article discusses experimental evidence for a discrete transition to channeling for 1.0-MeV protons in Si〈100〉

Dynamic networks and behavior: separating selection from influence.

A current problem in the analysis of behavioral dynamics, given a simultaneously evolving social network, is the difficulty of separating effects of partner selection from effects of social influence. In this paper we present a recently developed family of statistical models that enables researchers to separate the two effects in a statistically adequate manner. To illustrate our method we make use of a three-wave panel measured in the years 1995-1997 at a school in the West of Scotland. We are able to assess the strength of selection and influence mechanisms associated with friendship networks of substance-using adolescents

Marketing: principles and methods

x, 729 p. ; 24 cm

Z1 oscillations of the mean charge for isotachic ions in carbon foils

Article discussing Z1 oscillations of the mean charge for isotachic ions in carbon foils

K-shell x-ray-production cross sections in 6C, 8O, 9F, 11Na, 12Mg, and 13Al, by 0.75- to 4.5-MeV protons

Article discussing K-shell x-ray-production cross sections in 6C, 8O, 9F, 11Na, 12Mg, and 13AI, by 0.75- to 4.5-MeV protons

Collision-induced interaction cross sections of 1-7 MeV B₂ ions incident on an N₂ gas target

This article describes the measurement of collision-induced interaction cross sections for 1-7 MeV diatomic boron molecular ions incident on a nitrogen gas target by using a differentially pumped gas cell

Fabrication of silicon-based optical components for an ultraclean accelerator mass spectronomy negative ion source

Article discussing the fabrication of silicon-based optical components for an ultraclean accelerator mass spectonomy negative ion source