CRUSTACEANS

I haven’t yet investigated the water life of the backwaters so no information here!

Some basic biology – short and simple!

Crustaceans, like insects, are invertebrates , that is they have no internal skeleton, instead an outside protective ‘shell’ (exoskeleton) of a calcium-based mineralised substance, harder than that of an insect. Consequently they have to moult, that is, cast off their shell and form a new one in order to grow. Nearly all crustaceans live in the water – they include shrimps, crabs barnacles and crayfish. Land-living crustaceans are rare – they include woodlice, typically found in damp places.

Each segment of the body possesses pairs of jointed appendages, leg-like structures adapted for sensory activity, feeding, locomotion or sexual activity.

Fertilization is usually external, the eggs being simply released into the water. Sometimes they are sticky, attaching themselves to water weeds or sticking together in long strings but sometimes they are held in an egg sac (ovisac) underneath the female, released only when they hatch. The hatchlings have a larval form, quite unlike the adult, that metamorphoses gradually as it grows.