Intraspecific burrow plasticity of an intertidal population of Callianassafilholi (Crustacea : Decapoda : Thalassinidea) in relation to environmental conditions

Burrow morphology and intraspecific burrow plasticity in relation to enviro nmental conditions were examined for an intertidal population of Callianass a filholi Milne-Edwards, 1878 in southeastern New Zealand. Multivariate ana lysis of burrow features revealed no significant differences in burrow morp hology between seasons. However, dissimilarities between burrows from diffe rent seasons could be identified and included differences in lateral extent , total length, and volume of burrows. These size parameters each showed lo w values in winter, coinciding with low seawater temperature and high organ ic content of the sediment. There was no significant relationship between a ny of the three size parameters and sediment grain size or shore height of the burrow, but lateral extent and total length of the burrow were signific antly related to organic content of the sediment, decreasing with increasin g organic content. Furthermore, there was a significant positive relationsh ip between seawater temperature and total length of the burrow. Data from t he present study imply that intraspecific variation in burrow morphology fo r callianassids is dependent on environmental variables, which has conseque nces for the construction of useful burrow models.