Morphology of marine squat lobsters

The external and internal morphology of the marine squat lobsters is reviewed. External morphology of squat lobsters has been extensively studied, primarily in the context of taxonomic research. The external morphology of the body and appendages is illustrated and described for each marine squat lobster family. The internal morphology of squat lobsters has not been recently studied in detail; studies to date primarily cover Galathea and some aspects of Munida. Thus, coverage of internal morphology is focused on Galathea and includes muscular, digestive, respiratory, circulatory, reproductive, excretory, nervous and endocrine systems. Although the internal anatomy is known in detail only for Galathea, the conservative body plan of marine squat lobsters suggests a general applicability to other squat lobster families. Owing to the paucity of recent studies of internal anatomy of squat lobsters, many of the illustrations used herein are cited from classical works, which, along with their descriptive remarks, will hopefully stimulate extensive future studies. Functional morphology of pereopod 5 and gonopods 1–2 is still poorly known, as is the internal morphology of sense organs and endocrine system.