Size-dependent sex allocation in a simultaneous hermaphrodite parasite.
J Evol Biol
; 14(1): 55-67, 2001 Jan 08.
Article
em En
| MEDLINE
| ID: mdl-29280579
ABSTRACT
Most models of sex allocation distinguish between sequential and simultaneous hermaphrodites, although an intermediate sexual pattern, size-dependent sex allocation, is widespread in plants. Here we investigated sex allocation in a simultaneous hermaphrodite animal, the tapeworm Schistocephalus solidus, in which adult size is highly variable. Sex allocation was determined using stereological techniques, which allow measuring somatic and reproductive tissues in a common currency, namely volume. We investigated the relationships between individual volume and allocation to different reproductive tissues using an allometric model. One measure of female allocation, yolk gland volume, increased more than proportionally with individual volume. This is in contrast to the measure of male allocation, testis volume, which showed a strong tendency to increase less than proportionally with individual volume. Together these patterns led to sex allocation being strongly related to individual volume, with large individuals being more biased towards female allocation. We discuss these findings in the light of current ideas about size-dependent sex allocation in, primarily, plants and try to extend them to simultaneous hermaphrodite animals.
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Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article