Description

A very distinctive shrimp. It is moderately large, smooth and shiny. It is pale grey with contrasting dark brown-grey banding along the body and pincers and a prominent black patch with a white surround on the lateral side of the carapace.

Carapace. The base colour of the carapace is very pale grey. Viewed from above there is a dark transverse bar at the level of the black lateral patch. Forward of this are three curved bars that taper as they run diagonally forward on the side of the carapace in an irregular fashion. At their dorsal origin they may be solid or broken into two tear-shaped patches. The lateral view of the carapace is dominated by the circular black patch that lies on a white surround.

The abdomen. The segments of the abdomen are very pale grey. Between each a darker grey or bronze band extends the whole width, becoming broader laterally and sometimes terminating in a series of smaller circular black patches on pale grey. There may be a white band on segments 1 and 4.

The rostrum is pale grey with a dark grey band and a bandit’s mask across the eyes.

The appendages are bronze coloured, as are the antennae.

The pincers are pale grey with three dark grey-brown bands. Pollex and dactyl are white in the dominant claw, and mixed light and dark grey in the other.

The chelate second legs and walking legs are dark blue with yellow joints.

The tail fan is pale grey with the scutes outlined in darker grey. There is a dark spot on the endopod and proximal exopod. There are small setae.

The alternating bands on the abdomen and the black patch with a white surround on the carapace are distinctive. Heavy bodied, smooth and shiny.

Variation

There is variation in the degree of pigment but the species remains recognisable.

They can look very strange when there is a marked reduction in pigment, but the details of the pattern are clearly the same.

Similar Shrimps

This is a very distinctive shrimp and not readily confused with any other.

Nomenclature

Ryanskiy (2016) p9. has images of a similar looking shrimp and gives the name Alpheus species, common name Tail-spotted Snapping Shrimp. Length up to 3. 2 cm. Distribution South and Western Pacific – Philippines, Papua New Guinea.

Humann & DeLoach (2010) p85 has images of a similar looking shrimp and gives the name Alpheus species 5, common name Undescribed. Size to 3 cm. Papua New Guinea and Philippines.

Hayashi & Shiratori (2003) Alpheus species 1 from Japan.