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  • 1
    Electronic Resource
    Electronic Resource
    Biotic and abiotic factors affecting survival of early life history intervals of a stream-dwelling sunfish (1994)
    Springer
    Environmental biology of fishes 39 (1994), S. 153-159 
    Details
    ISSN: 1573-5133
    Keywords: Lepomis megalotis ; Centrarchidae ; Floods ; Brood mortality ; Fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Biotic interactions, such as competition and predation, and abiotic events, such as floods, both have important consequences for organisms inhabiting warmwater streams. Empirical studies can lead to better understanding of how these factors interact to affect distinct life history intervals of stream fishes. Survival of eggs, embryos and larvae in nests of longear sunfishLepomis megalotis was monitored in a section of Jordan Creek for four years. During two years characterized by low, relatively stable flow, nest failures could be attributed to biotic interactions. During two years with more variable flow, most brood losses occurred during floods. Flooding led to nest desertion and loss of offspring regardless of nest location. The number of nests constructed tended to be lower during years with more variable flow. The proportion of nests with successful broods did not differ between colonial and solitary nests. Variation in flow regime modifies the importance of biotic effects on survival of early life history intervals of longear sunfish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00004932
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  • 2
    Electronic Resource
    Electronic Resource
    Reproductive investment and somatic growth rates in longear sunfish (1992)
    Springer
    Environmental biology of fishes 35 (1992), S. 257-271 
    Details
    ISSN: 1573-5133
    Keywords: Life history ; Lepomis megalotis ; Reproductive investment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Allocation of energy to current reproduction at the expense of other functions, such as growth, can limit future reproductive potential. This cost of reproduction is a central concept of life history theory but has been difficult to verify in comparative field studies. Three levels of comparison of growth rates and reproductive investments were evaluated within and among populations of longear sunfish,Lepomis megalotis. All three demonstrated high levels of reproductive investment associated with reduced somatic growth. Within populations of central longear sunfish there are precociously mature sneaker makes and later maturing parental makes; sneakers have greater gonadosomatic index (GSI) values and slower somatic growth rates than parental makes. Between subspecies of longear sunfish grown under common conditions, there are differences in age at maturity and in the level of physiological reproductive investment that are associated with distinct differences in growth rates. Between populations of central longear sunfish inhabiting different sites, there are differences in the level of reproductive investment that are also associated with differences in somatic growth. Each comparison produced evidence that trade-offs occur between these life history traits, supporting the hypothesis that there is a cost of reproduction among male sunfish and suggesting that differences in strategies of reproductive investment contribute to variation in somatic growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00001892
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  • 3
    Electronic Resource
    Electronic Resource
    Thermal kinetic differences between allelic isozymes of malate dehydrogenase (Mdh-B locus) of largemouth bass, Micropterus salmoides (1983)
    Springer
    Biochemical genetics 21 (1983), S. 1143-1151 
    Details
    ISSN: 1573-4927
    Keywords: enzyme kinetics ; allelic isozymes ; malate dehydrogenase ; largemouth bass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two alleles are encoded at the malate dehydrogenase locus in largemouth bass, Micropterus salmodies. Populations in the extreme northern areas of the range of this fish are fixed or nearly fixed for the B1 allele, whereas populations in Florida are fixed for the alternative allele, B2. The MDH-B1B1 and MDH-B2B2 allelic isozymes were isolated by preparative starch gel electrophoresis and subjected to in vitro kinetic analyses. The apparent K m(oxaloacetate) for each of these allelic isozymes was determined at 25, 30, and 35° C. The K mvalues for both isozymes increased with increasing temperature and were not significantly different from each other at 25 and 35° C. However, at 30° C the K mvalue for the MDH-B1B1 allelic isozyme was higher than that for the MDH-B2B2 isozyme (i.e., 5.4×10−5 vs 3.3×10−5). These results are consistent with the hypothesis that the different environmental temperatures at different latitudes may be at least partially responsible for the north-south cline in Mdh-B allele frequencies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00488466
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  • 4
    Electronic Resource
    Electronic Resource
    Differences in tissue expressions of enzyme activities in interspecific sunfish (Centrarchidae) hybrids and their backcross progeny (1984)
    Springer
    Biochemical genetics 22 (1984), S. 931-956 
    Details
    ISSN: 1573-4927
    Keywords: interspecific hybrids ; fish ; enzyme locus expression ; tissue enzyme activities ; malate dehydrogenase ; lactate dehydrogenase ; glucosephosphate isomerase ; phosphoglucomutase ; developmental regulation ; gene regulatory evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The extent of naturally occurring variations of enzyme locus expression was determined for three tissues (liver, muscle, and eye) in two species of sunfish (Centrarchidae), the green sunfish (Lepomis cyanellus) and the redear sunfish (L. microlophus). The genetic basis for species differences in tissue enzyme specific activities of malate dehydrogenase (EC 1.1.1.37), lactate dehydrogenase (EC 1.1.1.27), phosphoglucomutase (EC 2.7.5.1), and glucosephosphate isomerase (EC 5.3.1.9) was investigated by determining enzyme specific activities in the tissues of the reciprocal F1 hybrids and of their backcross progenies. The specific activities for most enzymes in hybrids were intermediate between those of the parental species. Significant differences in enzyme specific activity were detected among the F1 progeny as well as those of backcrosses. Variations in specific activity levels in one tissue were often independent of variations in specific activities in a different tissue. However, the changes in the specific activities of different enzymes within the same tissue were often positively correlated. The tissue glucosephosphate isomerase activity differences appear not to be due to different functional contributions of the glucosephosphate isomerase allelic isozymes. Cluster analysis of distributions of specific activities revealed no simple Mendelian pattern of inheritance for control of tissue enzyme activity. Our results suggest a polygenic control of tissue enzyme specific activity levels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00499484
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  • 5
    Electronic Resource
    Electronic Resource
    Ontogeny of gene expression in Pomoxis (pisces: Centrarchidae) (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 119-128 
    Details
    ISSN: 0192-253X
    Keywords: Embryogenesis ; gene expression ; isozymes ; Pomoxis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The regulation of gene expression during embryogenesis was investigated in white and black crappie (Pomoxis spp.) and their reciprocal interspecific F1 hybrids. The schedule of morphological development and the timing of isozyme expression were compared among the two species and both reciprocal maternal half-sibling F1 hybrids. Although absolute rates of morphological development differed in response to incubation temperature, relative rates of morphological development (normalized to the onset of retinal pigment deposition) were similar among all crosses. Furthermore, these relative rates were similar to those previously documented for other centrarchid species. To assess differences in ontogenetic patterns of gene expression among the crosses, we examined expression for 39 enzymeencoding loci. Expression was not detected in the embryos for 16 loci due to low or nonexistent activity. Enzymatic activity from eight other loci were continuously detected throughout embryogenesis as a result of maternal enzyme in the egg. However, 15 loci initiated expression during the early development period investigated (fertilization through yolk sac absorption). We observed temporal variability in expression of these 15 loci among the crosses, either in the form of differential expression between parental species or as disturbances in the ontogeny of expression in interspecific hybrids. Such variability in expression suggests that some of the gene regulating mechanisms have diverged since Pomoxis species shared a common ancestral genome. © 1994 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020150202
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  • 6
    Electronic Resource
    Electronic Resource
    Multiple paternity in a wild population of northern water snakes, Nerodia sipedon (1992)
    Springer
    Behavioral ecology and sociobiology 30 (1992), S. 193-199 
    Details
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary For most animal species, a single mating is sufficient to fertilize all of a female's offspring. As a result, females do not usually increase their reproductive success with successive matings. However, multiple paternity has been discovered in many animal taxa. We demonstrate that the majority of female water snakes in a wild population mate with more than one male for each litter. Field observations indicated that a highly skewed operational sex ratio (3.6:1 M : F) during the breeding season, while not necessary for multiple paternity to occur, created ample opportunity for females to mate multiply. Protein electrophoretic analysis showed that at least 12 of 14 litters from naturally mated females had more than one father. Since male snakes can not force copulations, multiple matings seem likely to be the result of female choice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00166703
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