The burrow structure of the mud shrimp Callianassa subterranea (Decapoda: Thalassinidea) from the North Sea

Abstract

The burrow morphometrics of Callianassa subterranea (Montagu) were established from resin casts of burrows of mud shrimps collected from the North Sea and maintained in native mud in the laboratory for 90 days at 15°C. Each shrimp constructed a complex burrow consisting of a multi-branched network of tunnels connected to several inhalant shafts, each terminating in a funnel-shaped opening at the surface. In addition, a single (sometimes 2 or 3), much narrower exhalant shaft ended at the surface in a mound of expelled sediment. The mean diameters of tunnels, shafts and burrow volume were related directly to the size of the constructing shrimp. The only significant difference in burrow form between males and females was in the number of shafts (and corresponding inhalant openings); females constructed between 4 and 5, whereas burrows of males possessed between 6 and 8 openings. Comparison of present burrow descriptions from sandy sediments with those published previously for C. subterranea collected from mud, shows that burrows in mud are relatively simple (with a single shaft) and are deeper (30–81 cm) compared with these in sand (9–23 cm). Such burrow plasticity for a single species raises questions of the validity of recent attempts to develop a classification scheme for thalassinidean burrow morphology.

Keywords :

• Callianassa subterranea
• burrow structure
• North Sea