Coral Pistol Shrimp, Alpheus lottini

Coral Pistol Shrimp, Alpheus lottini. Shrimp collected from within Cauliflower Coral, Pocillopora elegans, at El Tule, Km 17, Baja California Sur, December 2009. Size: 3.0 cm (1.2 inches).

Phylogeny:  The Coral Pistol Shrimp, Alpheus lottini (Guéin and Méneville, 1829) is a member of the Alpheidae Family of Caridean Snapping Shrimp. The genus Alpheus is one of fifty-two genera in this large family, and there are three hundred forty-three species in this genus. The genus name Alpheus is Latinized Greek and can mean “whiteness”, “productive”, “gain”, “strength”, “fluidity”, the name of a Greek god, or refer to the Alpheus River. Some sources guess that “strength” was probably the meaning applied to these shrimp. This species is also known as the Coral Snapping Shrimp, Lottin’s Snapping Shrimp, and the Pocillopora Shrimp and in Mexico as Camarón Pistola de Coral and Camarón Chasqueadores.

Morphology:  The Coral Pistol Shrimp has a very distinct morphology due to its red color, a black band down its back, and spotted claws. Across the Indo-Pacific they are considered the most colorful species of shrimp. Their chelae are compressed, compared to the rounded chelae of the genus of snapping shrimp, Synalpheus. They have eyes that are hidden under an opaque shell. This species has the unique ability to be able to lose their single large claw and regenerate a replacement on the opposite side. The Coral Pistol Shrimp reach a maximum of 5.0 cm (2.0 inches) in length.

Habitat and Distribution: Coral Pistol Shrimp reside within Cauliflower Coral, Pocillopora elegans. More than one individual can be found within a single coral head. They are found in the intertidal zone, and to depths up to 17 m (50 feet). Coral Pistol Shrimp are found in the tropical regions of the Indian and Pacific Oceans.  In Mexican waters they range from La Paz, Baja California Sur, to Guatemala. They are absent from the west coast of the Baja Peninsula and the northern and central Gulf of California.

Diet:  Coral Pistol Shrimp feed on small arthropods, fish, zooplankton, coral mucous and detritus trapped in the mucous. In addition, they often feed on dead coral tissue, which also functions to keep the coral healthy.

Predation: Coral Pistol Shrimp are preyed upon by crabs, fishes, and octopuses.

Reproduction: Coral Pistol Shrimp are gonochoric (male or female for life). They reproduce sexually through indirect sperm transfer. The female molts, which leaves her temporarily with a soft shell that allows for mating. After molting she releases a pheromone to attract a male. The male deposits his sperm on the female and as she releases her eggs they are fertilized. The female carries the fertilized eggs in a brood pouch under her abdomen. Coral Pistol Shrimps form long-lasting monogamous relationships.

Ecosystem Interactions:  Coral Pistol Shrimp have a mutualistic relationship with their coral host. The shrimp finds shelter and food in the coral, while providing “housekeeping services” for the coral. In the Indo-Pacific Ocean, the Coral Pistol Shrimp are known to defend their host coral from the Crown-of-Thorns Starfish, Acanthaster planci. They pinch the starfish’s tube feet and snap off their arms. It is unknown if they do this in the Eastern Pacific. They are also known for their intraspecific communications with Coral Crabs of the genus Trapezia. The Coral Crabs are bigger and stronger and will not share a coral head with the shrimp unless the shrimp performs an appeasement dance. When one is present around tidal pools at low tide the presence of these animals is readily apparent as they generate very loud rapports that can be heard at distances of up to 180 meters (200-yards). It is believed that this snapping is utilized to stun small prey for subsequent consumption.

Human Interactions: Coral Pistol Shrimp have a very limited impact on human activities. From a conservation perspective they have not been evaluated, but they are common and widespread and should be considered to be of Least Concern.

Synonyms:  Alpheus laevis, Alpheus rouxii, Alpheus sublucanus, Alpheus thetis, Alpheus ventricosus, Cancer sublucanus, and Crangon latipes.