''Brachygobius sabanus'' is one of 8

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), ...

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 ...

in the ''

Brachygobius ''Brachygobius'' is a small genus of goby, gobies. They are popular aquarium fish where a number of species are sold as bumblebee gobies because their colours are similar to those of bumblebees. Morphology Bumblebee gobies range in size from 1.5 ...

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 ...

, which all share the common name of bumblebee fish or bumblebee goby due to their characteristic black and yellow stripes. Over the past two centuries, efforts to distinguish different species within the ''Brachygobius'' genus have occurred within

scientific literature Scientific literature encompasses a vast body of academic papers that spans various disciplines within the natural and social sciences. It primarily consists of academic papers that present original empirical research and theoretical ...

; ''Brachygobius sabanus'' was described within literature as its own species in 1958, by

Robert F. Inger Robert Frederick Inger (September 10, 1920 – April 12, 2019) was an American herpetologist. During his lifetime, he wrote numerous books and publications about herpetology. He was also the curator for amphibians and reptiles at the Field Museu ...

. Other gobies within the genus are ''B. nunus'', ''B. doriae'', ''B. alcocki'', ''B. sua'', ''B. xanthomelas'', ''B. aggregatus'', and ''B. kabiliensis''.

Taxonomy

Brachygobius sabanus belongs to the class Actinopterygii, known as the ray-finned fishes, which encompasses a vast number of fish species and represents half of all living vertebrates on Earth.Henderson, Struan “;” Dunne, Emma M. “;” Fasey, Sophie A. “;” Giles, Sam (2023). “The early diversification of ray‐finned fishes (Actinopterygii): hypotheses, challenges and future prospects”, Biological Reviews, 98(1), 284-315.Pūtys, Žilvinas “;” Ložys, Linas “;” Būda, Vincas (2015). “Respiratory response to the chemical cues of injured conspecifics and histology of skin in round goby, Neogobius melanostomus (Actinopterygii: Perciformes: Gobiidae)”, Acta ichthyologica et piscatoria., 45(4), 411-415. B. sabanus is part of the order of Gobiiformes, and are further categorized into the genus Brachygobius and species sabanus.Miller, Peter J. (1989). “The classification of bumble-bee gobies (Brachygobius and associated genera) (Teleostei: Gobiidae)”

Description

''Brachygobius sabanus'' has a very similar appearance to the other goby species in the ''Brachygobius'' genus, which all have relatively small bodies and distinctive black and yellow stripes.

Fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the this

, including ''B. sabanus'', are more cylindrical towards the anterior end of the body, and more compressed towards the posterior end. The

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple ani ...

is flattened between the

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

s, and the cranial roof sits beneath the dorsal axial

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

. They have two

nostril A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates ...

s near the front of their head, and an additional two pore-like nostrils posterior to the first set, close to the eye. As for their

dentition Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology ...

, they have caniniform

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

in both their

oral jaw Most bony fishes have two sets of jaws made mainly of bone. The primary oral jaws open and close the mouth, and a second set of pharyngeal jaws are positioned at the back of the throat. The oral jaws are used to capture and manipulate prey by b ...

and in their

pharyngeal jaw Pharyngeal jaws are a "second set" of jaws contained within an animal's throat, or pharynx, distinct from the primary or oral jaws. They are believed to have originated as modified gill arches, in much the same way as oral jaws. Originally hypoth ...

''Brachygobius sabanus'', in particular, has a yellow body with three black stripes and a black head. The first stripe overlaps with the black head and ends at the anterior half of the first dorsal fin; the last stripe spans down to the mid-ventral line posterior to the base of the anal fin; one additional black stripe sits between these. The first dorsal fin has black coloration at the anterior basal portion. Less than half of the

pectoral fins Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only b ...

, as well as the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s, are black. Finally, there is a thin yellow bar along the nape. ''B. sabanus'' has large

ctenoid scales A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as w ...

; there are between 24 and 27 mid-lateral scales and between 0 and 2 predorsal scales on the body, but no scales on the head. It has two

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

s, a rounded

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

that is no bigger than its head, and, like other gobies in the ''Brachygobius'' genus, its pelvic fins are fused together, creating a ventral disc. It can use this disc to attach itself to surfaces vertically and upside-down. ''B. sabanus'' shares the most similar appearance to ''Brachygobius doriae''. Differences between the two species can be found by observing the number of dorsal and anal rays, as well as mid-lateral scales; ''B. sabanus'' has more dorsal and anal rays than ''B. doriae'', but fewer mid-lateral scales. These two fish can also be differentiated by their coloration; ''B. sabanus'' has small black dots within the light dorsal coloration, known as dark dorsal saddles, which ''B. doriae'' does not possess. ''B. sabanus'' also shares very similar patterns of lateral-line sensory papillae with other ''Brachygobius'' species.

Distribution

''Brachygobius sabanus'' originated in, and is distributed across,

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

with well-established populations. However, it is not native to

Singapore Singapore, officially the Republic of Singapore, is an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...

, where many introduced ''B. sabanus'' populations have been found. Within Singapore, this goby has been located in the Poyan,

Tengah ''Tengah'' is an Indonesian and Malay word meaning "Central". It can be found in topography, e.g. * Jawa Tengah * Kalimantan Tengah * Papua Tengah * Sulawesi Tengah * Tengah Islands or Central Archipelago. * Tengah, Singapore * Tengah Air Base ...

Kranji Kranji is a suburb in northwestern Singapore, bounded by Sungei Kadut to the north, Turf Club to the east, as well as Lim Chu Kang and the Western Water Catchment to the west. It is located about from the city centre and its name came from the ...

, and

Upper Seletar Reservoir Upper Seletar Reservoir (, Chinese: 实里达蓄水池上段) is Singapore's third impounding reservoir, after MacRitchie Reservoir and Peirce Reservoir (now the Upper Peirce Reservoir and the Lower Peirce Reservoir). It is located within the Cen ...

s, the

Kranji Marshes The Kranji Marshes is a nature reserve in the northwest area of Singapore. Background A freshwater marshland, derived from the damming of the Kranji River to form the Kranji Reservoir Kranji Reservoir ( Chinese: 克兰芝蓄水池; ) is a r ...

, the

Sungei Buloh Wetland Reserve Sungei Buloh Wetland Reserve is a nature reserve in the northwest area of Singapore. It is the first wetlands reserve to be gazetted in Singapore (2002), and its global importance as a stop-over point for migratory birds was recognised by the in ...

, Banir (specifically, the Lorong Banir Stream in Seletar), and Sungei Seletar. It is commonly found in

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

ecosystems, including intertidal rock pools or waters with aquatic grasses, where it can hide from predators. Illustrated diagram of Brachygobius species

Illustrated diagram of Brachygobius species

Biology

''Brachygobius sabanus'' can grow to be up to (from the anterior end of the

snout A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, Rostrum (anatomy), rostrum, beak or proboscis. The wet furless surface around the nostrils of the n ...

to the base of the caudal fin) or (from the anterior end of the snout to the posterior end of the caudal fin). As for their swimming behavior, ''B. sabanus'' spends a substantial amount of time "perching" and/or "hopping" between spots. It has been known to exhibit

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

behavior, but is not solely benthic. It has also been observed to swim for extended periods of time, using its

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ (anatomy), organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

to aid in buoyancy. Additionally, ''Brachygobius sabanus'' is one of two goby species (out of eight that have been tested) that show a response to the chemical stimuli which are released when a

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...

is injured. Upon detecting the stimuli, it will reduce movements such as feeding and foraging behaviors, in order to be less noticeable to predators. Contrarily, when ''B. sabanus'' is exposed to chemical stimuli from a distantly related fish that has been injured, it increases feeding and foraging activity; this could mean that ''B. sabanus'' is good at detecting and ignoring false alarms. Extract from the skin of ''B. sabanus'' has also been used as a control in multiple studies to test these chemical stimuli abilities in other fishes.

Conservation status

''Brachygobius sabanus'' was listed as

Least Concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

in the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

Red List in 2018. It is reported to have well-established populations across Southeast Asia where it originated, as well as in

where it is non-native. There are also many populations of ''B. sabanus'' circulating in the

aquarium trade Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. It is a practice that encompasses the art of maintaining one's own aquatic ecosystem, featuring a lot of variety with various ...

, as it is a popular

ornamental fish Lists of aquarium life include lists of fish, amphibians, invertebrates and plants in freshwater, brackish and marine aquariums. In fishkeeping, suitable species of aquarium fish, plants and other organisms vary with the size, water chemistry and ...

. This aspect of human use may be the reason this species was introduced into Singapore habitats, as there are many facilities for farming, importing, and exporting ornamental fish around the

and the

Kranji Reservoir Kranji Reservoir ( Chinese: 克兰芝蓄水池; ) is a reservoir in the northern part of Singapore, near the Straits of Johor. It was a former freshwater river that flowed out into the sea that was dammed at its mouth to form a freshwater reserv ...

References

{{improve categories, date=November 2024 sabanus Fish described in 1958 Taxa named by Robert F. Inger