Intraspecific variation of life history parameters in the terrestrial isopod, Armadillidium vulgare

Abstract

Individual populations of the terrestrial isopod, Armadillidium vulgare, were studied in three Texas coastal prairie habitats: Chinese tallow forest, oak forest, and a Baccharis-grassland area. Time-specific life tables were compared for each population to determine intraspecific variation in life history parameters. Survivorship was greatest in the Baccharis area but density was lower and fluctuated less in this area than in the tallow or oak forests. Density in the oak forest was higher than in the tallow or Baccharis habitat. Density in the tallow and oak forests increased sharply during spring and summer and declined throughout the winter. Reproductive capacity of females in all three areas increased directly with body length but did not differ significantly between habitats. Density and reproductive performance of isopods in the tallow and oak forests was asynchronous with autumn leaf fall; this asynchrony may be a response to tannins leached from fallen leaves of these trees. Density and reproductive potential of isopods in the Baccharis-grassland, however, did not exhibit such marked fluctuations. Isopods in this latter habitat responded moderately to annual input of detritus during the fall.

Relationships between Trophic Niche Breadth and Reproductive Capabilities in a Population of Proasellus coxalis Dollfus (Crustacea: Isopoda)

“…This latter relationship agrees with the evidence already available on other animal species. It is known that the quality and the quantity of resources may affect different reproductive parameters of invertebrates, such as number or size of newborns per deposition (Thompson, 1982;Matsura & Morooka, 1983;Miller & Cameron, 1983;Murphy et al, 1983;Rushton & Hassall, 1983) or reproductive effort (Thompson, 1982). On the other hand, ingestion rate is generally a positive function of the available quantity of a resource (Holling, 1965).…”

“…Gerson & Thorens, 1982;Thompson, 1982;Matsura & Morooka, 1983;Miller & Cameron, 1983;Murphy, Laune & Ehrich, 1983;Rushton & Hassall, 1983). In turn quality and quantity of food are directly dependent on the trophic niche of individuals, a relationship that should be optimized by natural selection (e.g.…”

Cost of Breeding in Oniscid Isopods: A Partial Review

“…Likewise, any loss in embryos and marsupial mancae will presumably be regained by the mother (experimental evidence for this is still missing). This loss can partly be due to the fact that some embryos and mancae are not viable (see Miller & Cameron, 1983). In Armadillidium vulgare (Latreille, 1804), this loss was estimated to be 18%.…”

Intra- and inter-specific variability in some aspects of the reproduction of oniscid isopods

“…It can also be observed in the variability between members of different isopod populations belonging to the same species. Menon et al (1970) Meinertz (1951) Miller & Cameron (1983) Meinertz (1951) Meinertz (1951) Meinertz (1951 Variability in reproduction can be seen during the onset and duration of the breeding season (table I). This subject has been discussed previously (Dangerfield & Hassall, 1992;Achouri et al, 2008; also in tables 2, 3 in Warburg, 2012a, b).…”