Crustaceans

One in a series of concentric lines on outer surface of each side (valve) of carapace; each growth line marks a successive molt. Number of lines is of taxonomic importance. (distinct, indistinct; ...

One in a series of four partially fused ganglia of thorax region. Innervates thoracic appendage (thoracopod). Adjoined anteriorly to subesophageal ganglion and posteriorly to abdominal ganglion to ...

ventral ganglion

Animals; Crustaceans

One in a series of ganglion pairs of ventral nerve cord in thorax (thoracic ganglion) or abdomen (abdominal ganglion). Segmentally arranged, each giving rise to pair of nerves. Ganglion pairs may ...

cephalic hook

Animals; Crustaceans

One in a series of minute, anteriorly directed hooks located on underside of head (cephalon); restricted to anterolateral margins.

sternal gill

Animals; Crustaceans

One in a series of small structures projecting from ventral surfaces (sternites) of pereon segments. Considered to have respiratory or osmoregulatory function.