What is the function of the cephalic groove in a crayfish?

What is the function of the cephalic groove in a crayfish?

Cephalic groove – An indentation in the carapace between the head region and the thorax region. Cephalothorax – The combined head and thorax (this animal has no neck!). The cephalothorax contains the heart, gills, and stomach. Cheliped – One of two big claws used for defense and food handling.

What is the cervical groove on a crayfish?

(Taxon-specific: Order Decapoda) On carapace, well-defined, transverse groove separating gastric and cardiac regions. Considered to represent former border between two cephalic somites.

What is the function of a Cheliped?

The chelipeds are the large claws that the crayfish uses for defense and to capture prey. Each of the four remaining segments contains a pair of walking legs. In the abdomen, the first five segments each have a pair of swimmerets, which create water currents and function in reproduction.

Which appendages are cephalic in a crayfish?

The cephalic region contains 5 pairs of appendages:

• one pair of antennules (organs of balance, touch, and taste)
• one pair of longer antennae (organs of touch, taste, and smell)
• one pair of mandibles (crush the food by moving from side to side)

Can crayfish walk?

The walking legs of the crayfish are known as pereiopods and are attached to the animal’s thorax. In addition to their primary function of locomotion, the walking legs of crayfish are used to probe cracks and crevices in rocks for potential food sources.

Where do the nerves go when they leave the ganglion?

The ciliary ganglion is one of four parasympathetic ganglia in the head. It is located behind the eye. Nerve fibers leave the brain and enter the ganglia. These fibers synapse (a junction between nerves where they communicate) with neurons going to the eye.

What does the cervical groove do?

cervical groove Groove (sinuous but approaches linear at an angle) along side of carapace; differentiates head and thorax region.

Are crayfish Antennules Biramous?

Crustaceans have biramous appendages. Many groups of crustaceans have lost this extra appendage during subsequent evolution. The Order Decapoda have five pair of walking legs, and include the familiar crabs, lobsters, and crayfish. The first pair of appendages are usually modified as antennae.

What appendages deal with feeding in a crayfish?

Focus on the head, you may notice small appendages around the mouth. These are called the MAXILLIPEDS, and there are three sets, one on top of the other. These appendages help the crayfish manipulate food. The MANDIBLES of the crayfish are similar to the jaws of humans.

How many pairs of appendages do crayfish have?

Crayfish have 19 pairs of appendages, all built according to the same basic pattern but serving diverse…… In freshwater crayfishes the urine has the same concentration as far as the end of the labyrinth; from……

Can crayfish hear?

Crayfish are marvelous classroom organisms. Equipped with thousands of sensory bristles, some sensitive to chemicals and the others to touch, crayfish can smell, feel, and hear acutely, even though they are completely covered in a hard shell.