Brachygobius is a small 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...

 of gobies

Goby

The gobies form the family Gobiidae, which is one of the largest families of fish, with more than 2,000 species in more than 200 genera. Most are relatively small, typically less than 10 cm in length...

. They are popular aquarium

Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

 fish where a number of species are sold as bumblebee gobies because their colours are similar to those of bumblebee

Bumblebee

A bumble bee is any member of the bee genus Bombus, in the family Apidae. There are over 250 known species, existing primarily in the Northern Hemisphere although they are common in New Zealand and in the Australian state of Tasmania.Bumble bees are social insects that are characterised by black...

s.

Morphology

Bumblebee gobies range in size from 1.5 cm to 4 cm. They are generally coloured black with pale yellow to orange bands. Males are generally slimmer than females and often have more vivid colours, typically orange rather than yellow. Females may also have smaller and rounder heads. When spawning, the colours of the males become deeper, the orange bands becoming red in the case of Brachygobius doriae.

Taxonomy

At least 10 species have been recognised within the genus. They are informally divided by taxonomists into the dwarf Brachygobius nunus-species group

Species group

A species group is an informal taxonomic rank into which an assemblage of closely related species within a genus are grouped because of their morphological similarities and their identity as a biological unit with a single monophyletic origin.-Use:...

(e.g., B. nunus, B. aggregatus, and B. mekongensis) and the bigger Brachygobius doriae-species group (e.g., B. doriae, B. sabanus, and B. xanthomelas).

Ecology

Bumblebee gobies are found across Southern

South Asia

South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

 and Southeast Asia

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

 primarily in freshwater

Freshwater

Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 habitats but also in slightly brackish waters.

Reproduction

These gobies are oviparous. Eggs are deposited in a cave where they are guarded by the male. Clutch size is around 150-200 eggs. The eggs hatch after around seven days and the fry become free swimming another five to seven days later.

In the aquarium

Bumblebee gobies are popular aquarium

Fishkeeping

Fishkeeping is a popular hobby concerned with keeping fish in a home aquarium or garden pond. There is also a fishkeeping industry, as a branch of agriculture.-Types of fishkeeping systems:...

fish. A tank around 40 liters in size will house a dozen specimens comfortably. Under good conditions they can live in an aquarium for around 5 years. The most commonly traded species in the hobby belong to the Brachygobius doriae-species group but the smaller Brachygobius nunus is also traded occasionally. Although many aquarium books use the name Brachygobius xanthozona, this species is very rare in the wild and is not commercially traded.