Thalassinidean shrimp construct species-specific burrows which vary in morphology from simple 'U' or 'Y' shaped tubes to more complex tiers of galleries or reticulate branches. Data on the burrow architecture of 44 species in 10 genera indicates that the morphological patterns of thalassinidean burrows are more diverse than previously recognized. Based on a review of these data and the existing information on thalassinidean feeding, we propose several generalizations in the form of a heuristic model relating burrow architecture and trophic mode in these fossorial decapods. Despite moderate levels of morphological variation between species, thalassinidean burrows can be categorized into 6 major groups based on their morphological characteristics. The 6 burrow types are distinguishable based on the presence or absence of (1) surface sediment mounds at excurrent openings, (2) seagrasses in chambers or the burrow lining, and (3) a simple 'U' shaped burrow design. Although relatively little is known about the functional significance of the different architectural patterns, each burrow type may be indicative of one of the 3 general trophic modes utilized by burrowing shrimp: (1) deposit feeding, (2) drift catching, and (3) filter/suspension feeding. Two different types of burrows are discernible within the mound-producing, deposit-feeding group, 3 distinct burrow morphotypes are associated with filter/suspension feeding, and the 6th burrow morphotype is produced by the drift catchers. The ecological significance of these 6 burrow types is discussed in addition to the effects of various environmental parameters on intraspecific variation in burrow morphology.
