Achaeopsis spinulosa, the hotlips spider crab, is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of crab

Crab

True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...

 in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Inachidae

Inachidae

Inachidae is a family of crabs, containing 39 genera:*Achaeopsis Stimpson, 1857*Achaeus Leach, 1815*Anisonotus A. Milne-Edwards, 1879*Anomalothir Miers, 1879*Bothromaia Williams & Moffitt, 1991...

, found only around the South African coast. It is the only species

Monotypic

In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 in the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Achaeopsis.

Distribution

The crab is found from False Bay

False Bay

False Bay is a body of water defined by Cape Hangklip and the Cape Peninsula in the extreme South-West of South Africa.- Description and location :...

 to Durban

Durban

Durban is the largest city in the South African province of KwaZulu-Natal and the third largest city in South Africa. It forms part of the eThekwini metropolitan municipality. Durban is famous for being the busiest port in South Africa. It is also seen as one of the major centres of tourism...

, subtidally to 43 metres (141.1 ft). It is endemic to this region.

Description

Achaeopsis spinulosa is commonly known as the hotlips spider crab because of the vivid red marking around its mouth. It is a small spider crab with relatively long but quite sturdy legs. It may grow to 70 millimetres (2.8 in) across. Its carapace is rounded, tapering to a blunt tip. Its pincers are raggedly striped in white and red.

Ecology

The crab decorates its body with sponges, hydroid

Hydroid

-Marine biology:Hydroids are a life stage for most animals of class Hydrozoa, small predators related to jellyfish.-Botany:In mosses, hydroids form the innermost layer of the stem of long, colourless, thin walled cells of small diameter.The cells are dead and lack protoplasm.They function as water...

s, or algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

, improving its camouflage

Camouflage

Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...

. It is seldom seen without some form of decoration. It is often found among striped anemones and on sea fan

Sea fan

A gorgonian, also known as sea whip or sea fan, is an order of sessile colonial cnidarian found throughout the oceans of the world, especially in the tropics and subtropics. Gorgonians are similar to the sea pen, another soft coral. Individual tiny polyps form colonies that are normally erect,...

s.