''Alpheus randalli'' is a species of

snapping shrimp Alpheidae is a family of caridean snapping shrimp, characterized by having asymmetrical claws, the larger of which is typically capable of producing a loud snapping sound. Other common names for animals in the group are pistol shrimp or alpheid s ...

in the family Alpheidae. It lives in the

Marquesas Islands The Marquesas Islands (; french: Îles Marquises or ' or '; Marquesan: ' ( North Marquesan) and ' ( South Marquesan), both meaning "the land of men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in th ...

and parts of the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

, including the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, V ...

, in

association Association may refer to: *Club (organization), an association of two or more people united by a common interest or goal *Trade association, an organization founded and funded by businesses that operate in a specific industry *Voluntary associatio ...

with a goby of the genus ''

Amblyeleotris ''Amblyeleotris'' is a genus of fish in the family Gobiidae found throughout the Indo-Pacific region. This is the largest genus of the shrimp gobies or prawn gobies, so-called because of their symbiotic relationship with certain alpheid shrimps. ...

''. The shrimp is transparent or white with prominent red markings.

Description

''Alpheus randalli'' is a medium-sized snapping shrimp growing to about long. The rostrum of ''Alpheus randalli'' is half as long again as it is broad and the

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

is not laterally compressed. The chelipeds are asymmetric, one carrying a massive snapping claw. The background colour of this shrimp is white or transparent with red bands and spots on the rostrum and both large and small chelipeds. There are further bands of white and red on the abdomen and the tips of the

uropod Uropods are posterior appendages found on a wide variety of crustaceans. They typically have functions in locomotion. Definition Uropods are often defined as the appendages of the last body segment of a crustacean. An alternative definition sugge ...

s are red. The tips of the thoracic appendages are yellowish-green.

Distribution

''Alpheus randalli'' was first described in 1981 from the Marquesas Islands in the Indian Ocean where it was found living at a depth of in association with a previously undescribed species of goby in the genus ''Amblyeleotris''. This has now been given the name Randall's prawn goby (''Amblyeleotris randalli'').

Biology

The goby and shrimp share the same extensive burrow which the shrimp excavates in sandy or silty areas of the seabed. It has one or more openings, the positions of which are constantly changing as the shrimp engages in burrowing activities. During the day the goby rests on the burrow floor with its head by the opening or may emerge further. It feeds by picking small invertebrates out of the substrate that has been disturbed by the shrimp or by taking mouthfuls of sediment and extracting edible organisms and detritus. The shrimp is mainly a detritus feeder. The shrimp has poor sight and is alert to the actions of the goby. The shrimp is more vulnerable to predation and is quick to retreat to safety even when the danger level is low. If the fish swims into the burrow head first to escape more immediate danger, the shrimp darts in immediately. At night both retreat into the interior of the burrow and the entrances are sealed. The goby probably lays its eggs in a mass in the burrow as happens with other members of this genus. The shrimp lives singly in the burrow and at breeding time probably make an opening close to an adjoining burrow occupied by a shrimp of the opposite sex. The female shrimp carries her eggs under her abdomen.

References

External links

* {{Taxonbar, from=Q3656164 Alpheidae Crustaceans of the Indian Ocean Crustaceans described in 1981