''Paguristes puncticeps'' is a

hermit crab Hermit crabs are anomuran decapod crustaceans of the superfamily Paguroidea that have adapted to occupy empty scavenged mollusc shells to protect their fragile exoskeletons. There are over 800 species of hermit crab, most of which possess an a ...

, in the family

Diogenidae The Diogenidae are a family of hermit crabs, sometimes known as "left-handed hermit crabs" because in contrast to most other hermit crabs, its left chela (claw) is enlarged instead of the right. It comprises 429 extant species, and a further 46 e ...

. It is found in shallow waters in the tropical western Atlantic Ocean, the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

and the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

. Like other hermit crabs, it lives inside an empty mollusc shell, which it changes periodically as it grows.

Description

''P. puncticeps'' is a large hermit crab, growing to a length of , including the limbs and

chelae A chela ()also called a claw, nipper, or pinceris a pincer (biology), pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are ...

(claws). It is a dark red or rusty-brown colour with the hairy

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 ...

and limbs spotted boldly with white. The antennae and eye stalks are also dark red and the irises of the eyes are blue. In most members of this family, the left chela is larger than the right one, but in the case of ''P. puncticeps'', there is little difference in size between the two.

Distribution and habitat

''P. puncticeps'' occurs in the tropical western Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. Its range extends from Florida to Brazil and includes Cuba, Guadeloupe, Martinique and Saint-Martin. Its depth range is from the low tide mark down to about . It usually occurs in

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

habitats.

Ecology

''P. puncticeps'' is a scavenger and

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

, feeding on any animal or vegetable matter that it finds. Breeding takes place throughout the year. The first larval stages take place in the egg, which then hatches into a

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic zoeal larva. When fully developed, this settles on the seabed and undergoes

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

into a juvenile, which will need to find a small vacant shell in which to live. The empty shells of the

queen conch ''Aliger gigas,'' originally known as ''Strombus gigas'' or more recently as ''Lobatus gigas'', commonly known as the queen conch, is a species of large sea snail, a marine gastropod mollusc in the family of true conches, the Strombidae. Th ...

(''Aliger gigas'') are often used by this hermit crab, and shells of the Florida horse conch (''Triplofusus papillosus''), the largest gastropod mollusc in the northern

, are favoured by larger individuals, as are the large snails on which this mollusc preys. A factor limiting populations of hermit crabs in any area is often the availability of empty gastropod shells for them to occupy. Cephalopods such as the

common octopus The common octopus (''Octopus vulgaris'') is a mollusc belonging to the class Cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. The ...

(''Octopus vulgaris'') and the Caribbean reef octopus (''Octopus briareus'') feed on lobsters, crabs, hermit crabs, and molluscs, often carrying their prey back to their den, where they deposit the inedible parts nearby, forming a

midden A midden (also kitchen midden or shell heap) is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, mollusc shells, potsherds, lithics (especially debitage), and other artifacts and ecofact ...

. They often extract their prey through the aperture of the shell, leaving the structure intact. The midden constitutes a source of empty shells available for use by hermit crabs, and ''P. puncticeps'' individuals have been observed carrying empty shells away from the pile. The middens also attract hermit crabs which feed on food scraps left by the octopus, but feeding close to the octopus den is a risky business. Smaller hermit crabs (shield length less than ) sometimes live inside the octopus den, feeding on food scraps discarded by the octopus.

References

{{Taxonbar, from=Q4472447 Diogenidae Crustaceans described in 1901 Crustaceans of the Atlantic Ocean