The burrows of alpheid shrimp associated with gobiid fish in the northern Red Sea

The burrows of 4 sympatric associations of alpheid shrimp (Alpheus djiboutensis 1 and 2, and Alpheus sp. A and B) and non-burrowing gobiid fish were studied in the lagoon of a narrow fringing reef, in the northern Red Sea. Epoxy resin casts were used to determine the subterranean structure of burrows. The burrows were irregular, and in close contact with hard objects within the substrate. The number and structure of openings and their daily displacement were type-specific. On the other hand, no type specificity was observed in the deeper parts of the burrow. The mechanism of the formation of new openings by the combined activities of the fish Cryptocentrus sungami and the shrimp A. djiboutensis 2 is described. A positive correlation in the size of the partners seems to be due to competition of fish for larger burrows.