The adult female of M. intestinalis is about 8 mm long with smoothly rounded posterior corners of the head, whereas the adult female of M. orientalis is 10-12 mm long with a pair of slender processes extending from the posterior corners of the head. In the adults of both sexes, the second antenna has three segments in M. intestinalis and two segments in M. orientalis . The posterolateral thoracic protuberances are more prominent in M. orientalis , except for the first pair which is absent in male M. orientalis . The adult male of M. porrecta has reduced posterolateral thoracic protuberances that are almost undiscernible. The claw of the maxilliped is short, stout and strongly hooked in comparison to the elongated and not strongly hooked maxilliped claw of male M. intestinalis and M. orientalis .
Examine body cross sections for large copepods within the lumen of the gut.
Copepods may attach by hooked appendages to the intestine wall. Focal tissue metaplasia may be present in the intestinal epithelium. Digestion of tissues will expose copepods for easy quantification. This process is recommended for large scale surveys rather than diagnostics. No known methods of prevention or control.