Lysmata amboinensis

Lysmata amboinensis is an omnivorous shrimp species known by several common names including the Pacific cleaner shrimp. It is considered a cleaner shrimp as eating parasites and dead tissue from fish makes up a large part of its diet. The species is a natural part of the coral reef ecosystem and is widespread across the tropics typically living at depths of 5–40 metres (16–131 ft). L. amboinensis can reach a body length of 5–6 centimetres (2.0–2.4 in) and have long white antennae. Mature shrimp are pale in colour with longitudinal bands on their carapace; one central white band with wider scarlet red bands on either side. The shrimp has a long larval stage and unusual sexual maturation, initially being male but becoming a functional hermaphrodite once mature. L. amboinensis is popular in home and public aquaria where it is commonly referred to as the skunk cleaner shrimp; this is due to its striking colours, peaceful nature, and useful symbiotic cleaning relationship which can also be witnessed in captivity. Adult shrimp can reach a body length of 5–6 centimetres (2.0–2.4 in) with two pairs of long white antennae. The body and legs are pale amber in colour with longitudinal bands on the carapace: one central white band is flanked by wider scarlet red bands. There are several symmetrical white spots on the red tail. The most anterior antennae fork into two making the shrimp appear to have three pairs of antennae. As with all decapods there are 10 pairs of walking legs, with the most anterior pair having forceps (pincers). Anterior to the walking legs are a pair of white maxillipeds used for feeding. Underneath the thorax behind the walking legs are paired pleopods (swimmerets) used for swimming and brooding eggs. L. amboinesis have a pair of stalked eyes though experiments suggest they have coarse vision and are colour blind; this low spatial resolution makes it unlikely they can see the striking patterns of other shrimps or tropical fish. L. amboinensis is native to coral reefs across the tropics including the Red Sea and the Indo-Pacific Ocean. They live on tropical coral reefs between depths of 5–40 metres (16–131 ft) and are typically found in caves or reef ledges. L. amboinesis lay eggs which the adult shrimp keep attached to their pleopods. The early larvae are called nauplii which hatch into more developed larvae called zoeae and go through a free-floating planktonic stage. During this time they feed on other plankton and moult through 14 identified stages growing to approximately 2 centimetres (0.79 in) in length over 5–6 months. At this point the larvae will settle and metamorphose into a more mature form, though not yet the adult state. This is achieved after several moults which occur every 3–8 weeks. Each shrimp starts out as a male, but after a few moults will become a hermaphrodite allowing them to function as both male and female in interactions with another shrimp; these shrimp have no pure female form. This form of sexual maturation is scientifically described as 'protandric simultaneous hermaphroditism' and is unique to Lysmata shrimp amongst other decapod crustaceans. In one spawning, adult shrimp will lay between 200–500 eggs which are initially attached to the pleopods and are greenish in colour; the eggs swell and lighten in colour before hatching and a few will turn silver on the day of hatching. The eggs hatch around dusk releasing 3–4 millimetres (0.12–0.16 in) long larvae into the free-floating pelagic zone.