摘要:

We examined the survival, size, and agonistic behaviour of faster and slower developing rainbow trout (Salmo gairdneri) in an artificial stream channel with a simulated redd. The analysis was performed at two levels: between three full‐sib families genetically marked at a hexosaminidase locus, and within families segregating for a regulatory allelePgml‐t(b)that is associated with faster developmental rate. The families differed significantly in their hatching times but showed little variation in emergence times. Fishes with thePgml‐t(b)allele hatched and emerged significantly earlier than their full‐sibs without the allele. Despite the mortality of at least 50% of emerged fishes in the selection experiment, there was no significant difference in survival between either the three families or fishes with different genotypes at thePgml‐tlocus. However, fishes from the faster developing family and those with thePgml‐t(b)allele had significantly higher levels of agonistic behaviour and had a tendency to be larger than slower developing

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00808.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The hypothesis that dimorphically coloured, cryptic moths select appropriate rest sites by comparing their body scales to substrate reflectance was tested using typical and melanic morphs of the peppered moth,Biston betularia(L.). Experiments designed to block the individual's inspection of its inherited colour phenotype do not support Kettlewell's contrast/conflict (self‐inspection) hypothesis. Instead, tracking of marked moths over successive days revealed individual differences in rest‐site selection which were not related to treatments, experience (imprinting), nor closely to a moth's inherited colour pattern. Differences between family broods indicate that some genetic bias in background selection exists. The production of artificially selected lines with consistent but opposing preferences will allow us to investigate the co‐evolution of pattern and beha

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00809.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The grasshoppersChorthippus parallelus parallelusandC. p. erythropusform a narrow hybrid zone in the Pyrenees. They differ in several characters of the pattern and structure of male stridulation and in the morphology of the stridulatory file. These characters are considered to be involved in the species' mate recognition system.Crosses have been made between a PyreneanC. p. erythropuspopulation and twoC. p. paralleluspopulations, one in the Pyrenees and one in the Massif Central. Reciprocal Fls and backcrosses have been examined for a set of stridulation and associated morphological characters. The crosses confirm that the subspecific differences have a genetic basis and suggest that they are polygenically determined. However the mode of inheritance is not simple. There is evidence for dominance and epistatic effects and for sex‐linkage or maternal effects. Genetic correlations exist between some pairs of characters in the backcrosses.These results are discussed in the context of the hybrid zone and in relation to the general problem of the evolutionary divergence of mate recognition system

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00810.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The most derived fruit‐eating bats have small canines, wide palates and molars with a distinctive labial rim. Paracone and metacone have moved from a dilambdodont position in the middle of the tooth to the labial side of the tooth where they form the labial cutting edge. Along with the well‐developed and close fitting labial cutting edges of the premolars and canines, this cutting edge skirts nearly the entire perimeter of the palate. The labial rim of the lower teeth fit inside the labial rim of the upper teeth like two cookie cutters nesting one inside the other. Frugivores have a greater allocation of tooth area at the anterior end of the toothrow, while animalivorous species have more at the posterior end of the toothrow. The area occupied by canines of predators of struggling prey is greater than that for bats that eat non‐struggling prey like fruit. In addition, frugivores have wider palates than long while many carnivores have longer palates than wide. Omnivores appear to have a more equal allocation of space to more kinds of teeth, particularly the incisors and non‐molariform premolars, on the toothrow than do frugivores or animalivores. The mechanical nature of different food items is discussed and the suggestion made that describing foods in terms of their texture may be more important in tooth design than whether they are fruit or insect or ver

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00811.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The relationship between testes size, ejaculate quality (volume, sperm concentration, number of sperm per ejaculate) and sperm competition in birds was analysed using data collected in artificial insemination studies. I hypothesized that ejaculate quality, because of natural selection, should be superior in species with intense sperm competition compared with other species. In regression analyses, testes weight increased with body weight, with an exponent less than one, and ejaculate volume increased with testes weight with an exponent not significantly different from one, whereas sperm number per ejaculate increased with testes weight with an exponent larger than one. Species with relatively large testes also produced ejaculates with a high sperm concentration. Monogamous species with a relatively low intensity of sperm competition copulate rarely, but deliver ejaculates with a relatively large number of sperm. Monogamous species with a high intensity of sperm competition copulate frequently, but produce ejaculates with a relatively small number of sperm. Males of polygynous species, which also experience intense sperm competition, copulate rarely with specific females, but produce many ejaculates per male each with a relatively small number of sperm.

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00812.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

We examined the relationship between multilocus heterozygosity and several components of fitness in the Arlee strain of rainbow trout(Salmo gairdneri). There is a significant negative association between multilocus heterozygosity and standardized rate of oxygen consumption (VO2) in 168 fish produced from a pooled mating between 55 females and 60 males. Fish which are more heterozygous also tend to be longer, heavier and have a significantly greater condition factor than fish which are less heterozygous. However, no relationship is evident between VO2, weight, length, condition factor and multilocus heterozygosity within two full‐sib families. These results indicate that the larger size of more heterozygous fish may partially be attributed to the increased metabolic efficiency in heterozygotes compared to homozygotes and that these differences may only be detectable at the population level. More heterozygous females of the same age also have larger eggs. Energy conversion may be more efficient in more heterozygous females resulting in the production of larger eggs. The prediction that fish with faster developmental rates are metabolically more efficient and, therefore, have lower VO2was also tested. Earlier hatching fish from five families do not have significantly lower VO2than their later hatching full‐s

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00813.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00814.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1988.tb00815.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY