The loach goby, ''Rhyacichthys aspro'', is a

goby The Gobioidei are a suborder of percomorph fish. Many of these fishes are called gobies. It is by far the largest and most diverse order within the order Gobiiformes, and one of the most diverse groups of ray-finned fish in general. The subord ...

belonging to the family

Rhyacichthyidae The Rhyacichthyidae or loach gobies are a small family of perciform fish in two genera. The three species all inhabit rivers and streams, often with fast flow. ''R. aspro'' is widespread in Western Pacific region (China and Japan to New Guinea ...

. It is not fished commercially.

Taxonomy

The loach goby is one of the two

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

classified under the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Rhyacichthys ''Rhyacichthys'' is a genus of fish belonging to the family Rhyacichthyidae. They occur in the Indo-Pacific region. Species *'' Rhyacichthys aspro'' (Valenciennes, 1837) - loach goby *''Rhyacichthys guilberti ''Rhyacichthys guilberti'' is a g ...

'' in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

. Thacker and Hardman's study of the

molecular phylogeny Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

of gobies indicates the loach goby is the most primitive member of the Gobioidei.

Description

The loach goby is long. It has eight dorsal spines, eight or 9 soft dorsal rays, one anal spine, and eight or 9 anal rays. The head is flattened vertically, with a snout and small eyes. The mouth is on the underside and has a fleshy upper lip. The body is laterally compressed toward the slightly forked tail; it has a well-developed

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

system. The pelvic fins are separate, with enlarged musculature. In colour, it is light brown, with darker, longitudinal stripes on its flanks. Also, dark stripes occur on the dorsal, caudal, and pectoral fins.

Distribution and habitat

The loach goby lives in tropical waters between 24°N and 13°S, ranging from China and south Japan, through the Philippines and Indonesia, to

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

and the Solomons. It inhabits fast-flowing streams in mountainous terrain.

Habits

The loach goby normally clings to rocks in fast-flowing streams, using the rocks as hiding places when threatened. It makes swift darting movements. It eats the

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

growing on the rock surfaces.

References

External links

Fishbase
{{DEFAULTSORT:Loach Goby Rhyacichthyidae Fish described in 1837