| Whitetail dascyllus | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Blenniiformes |
| Family: | Pomacentridae |
| Genus: | Dascyllus |
| Species: | D. aruanus |
| Binomial name | |
| Dascyllus aruanus | |
| Synonyms | |
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Dascyllus aruanus, known commonly as the whitetail dascyllus or humbug damselfish among other vernacular names, is a species of marine fish in the family Pomacentridae. [1]
Whitetail dascyllus is up to 10 centimetres (3.9 in) in length but its common size is 6 centimetres (2.4 in) and is white with three black vertical bars. [2] Unfortunately, it is often mistaken for the Dascyllus melanurus, which has four black stripes instead of three. Dascyllus aruanus resides within the Perciformes order in the Pomacentridae family, most taxonomically related to the Hypsypops rubicundus (Garibaldi) and the Amphiprion ocellaris (Ocellaris clownfish). They have a small mouth, a flat spine, a white body with a large white spot between the eyes, and a black spot on the pelvic fin and caudal peduncle. [3]
In the first year of life, the damselfish grows to be about 6 centimeters. However, it is fully grown by the end of its second year and remains at around 10 centimeters for another three to four years until it dies. The colors remain the same throughout their lives and serve multiple purposes. The bold contrast of black and white attract fish of the same species, yet display as a sign of toxicity to potential predators. [4]
Associated with coral reefs, most usually in groups above Acropora coral heads. The black and white damselfish maintains a symbiotic relationship with its coral reef through exchange of nutrients for shelter. As planktivores, the humbug acts as a “gardener” by grazing on unwanted algae and excreting its waste in the form of phosphorous and ammonium. In return, they can use the coral reef for protection and shelter, leaving only when necessary. To remain in the safety of the reef, the humbug will feed on waste and small prey nearby. [5]
Dascyllus aruanus inhabits most of the Indo-Pacific territory ranging from the Red Sea to New South Wales. [6] They live in small groups of around 30 individuals and prefer smaller territories in the shallow coral reefs. The shallow reefs can range from around one to ten meters deep and the inhabiting damselfish rarely stray far from the home they were born in. [7]
Most of these coral reefs are smaller with less species diversity. The humbug damselfish are particularly territorial and will act accordingly to protect their coral shelters. However, the humbug is found to reside in some of the same coral as Dascyllus marginatus. Instead of seeing this fish as competition, they adapted similar behaviors and are able to cohabitate with each other efficiently. [8] The coral reef is species-rich and abundant in nutrients, making it an excellent habitat for many different fish, including the Dascyllus aruanus.
{the accompanying map is erroneous as it shows the Caribbean}
As a group that will stay at the same coral reef for their entire life, the Dascyllus aruanus species is very aggressive when it comes to their territory. All resources are heavily guarded and any unfamiliar species is seen as a threat. Living in a coral reef in shallow waters can make protection a full time job for some of these fish, making them extremely observant and wary. Some individuals are more aggressive than others, making an attack first response rather than observing for warning signs. [9] As a species residing in shallow waters, there are multiple species of fish that come across the damselfish habitat. The humbug recognizes individuals of its own species by the dominant color pattern of the black stripes rather than movement. [10] With this ability, the humbug can reserve its energy for the unknown species it will encounter.
The social behaviors of the damselfish begin at a very young age. Juveniles stay in their schools and heavily rely on each other at all times. Communication in these groups is used for warning signals when threats come across or when food is available around the shelter. Similar to adults, juveniles remain close to their home at all times and will retreat at any sign of danger. [11] Hierarchies are also used in these schools with an early establishment of dominance based on size. Larger fish (males and females) lead the foraging groups and get first priority of food, which usually corresponds to larger size prey. Smaller fish stay in the back of the school and eat smaller and fewer prey than the others. [12] These behaviors are continuously utilized as the damselfish evolves into adulthood.
Unlike other fish, black and white damselfish do not have a spawning season. Mating occurs daily, with females mating with multiple males in a season. A new batch of eggs can be produced every two days with up to two thousand eggs per batch and males court females constantly. Male preference is the only factor affecting the consistency of spawning, with non-random mating selected by females. However, many factors come into play when selecting a male. Courting and mate copying are the two dominant behaviors that correlate to female preference. Mate copying is when a female will mate with a male that just previously mated with another female. Males with higher courtship rates positively correlate with higher reproductive success. [13]
Males use the “signal jump” to attract mates by quickly rising up a water column before swimming down. On the other hand, males that have recently mated are more likely to mate again with a female. Females prefer to spawn at sites that already contain eggs, signifying that a male has higher qualities than others in successful spawning with another female. This copying strategy reduces energy and effort for females to choose a mate while also reducing the chances of selecting a low-quality mate, increasing the reproduction rate and success of a female. [14] Males are highly territorial of their nesting sites and aggressive towards other males when courting a female. They also build and guard the nests once spawning is complete. This constant and efficient reproduction system is likely a large contributing factor to the stable conservation status of Dascyllus aruanus.
As climate change continues to raise ocean temperatures, the humbug's lifestyle dwindles in response. Despite maintaining a status of Least Concern according to the IUCN Red List, [15] the damselfish population remains susceptible to thermal stress and habitat loss by coral bleaching. According to a climate change study conducted in 2020, warmer oceans will result in an increase in mobility and a decrease in aggression by Dascyllus aruanus. The change in behavioral patterns are predicted to shift the social dynamics of a variety of fish that live in cohabitation with the humbug. [16]
While coral reefs are one of the most critical habitats put at risk by climate change, its relationship with Dascyllus aruanus increases its resistance to these effects. When residing in the coral branches, the humbug damselfish will excrete nutrients such as phosphorous and ammonium. Coral with these nutrients are able to store more macromolecules which not only increases their energy levels, but also their resistance to thermal stress. The symbiotic relationship between Dascyllus aruanus and its habitat is beneficial and critical to both species as ocean waters continue to rise in temperature. [17]
The current hope of this species rests in their plasticity, as the black and white damselfish have been found to adapt to dead coral colonies. [18] This ability makes them more adaptable to different environments, but the extent of how long they could maintain this change is yet to be determined. The significance of the nutrients provided by living coral has not been quantified, but the humbug damselfish does prefer living coral reefs to dead ones. Not only can they adapt to dead coral, but they can also adapt in their diets. While originally planktivores, black and white damselfish will also eat other small fish and debris in their habitats. Over time, they have developed a broad range of diet and living conditions. These adaptations will help preserve the Dascyllus aruanus, but the effects of climate change could still put them at risk of endangerment or extinction. Overall, the future of the humbug, like many other species, remains uncertain. The current focus of the scientific community is preserving the coral reefs that serve as the habitat for many different species.
They are called aquarium 'Starter fish' as they are quite tolerant of variable conditions and aid in conditioning the tank environment for less hardy fish. These fish have been reared in captivity. They can be territorial with other fish. The adult is quite aggressive.
Pomacentridae is a family of ray-finned fish, comprising the damselfishes and clownfishes. This family were formerly placed in the order Perciformes but are now regarded as being incertae sedis in the subseries Ovalentaria in the clade Percomorpha. They are primarily marine, while a few species inhabit freshwater and brackish environments. They are noted for their hardy constitutions and territoriality. Many are brightly colored, so they are popular in aquaria.
The Garibaldi, known historically also as the Catalina goldfish and marine goldfish and now commonly as the Garibaldi damselfish is a species of bright orange fish in the damselfish family. It occurs in the subtropical northeastern part of the Pacific Ocean. The Garibaldi is the official marine state fish of California, as of 1955, and has since been protected in California coastal waters from recreation and commercial fishing.
Damselfish are those within the subfamilies Abudefdufinae, Chrominae, Lepidozyginae, Pomacentrinae, and Stegastinae within the family Pomacentridae. Most species within this group are relatively small, with the largest species being about 30cm in length. Most damselfish species exist only in marine environments, but a few inhabit brackish or fresh water. These fish are found globally in tropical, subtropical, and temperate waters.
Thalassoma bifasciatum, the bluehead, bluehead wrasse or blue-headed wrasse, is a species of marine ray-finned fish, a wrasse from the family Labridae. It is native to the coral reefs of the tropical waters of the western Atlantic Ocean. Individuals are small and rarely live longer than two years. They form large schools over the reef and are important cleaner fish in the reefs they inhabit.
The New Zealand demoiselle, Chromis dispilus, is a damselfish of the genus Chromis, found between North Cape and East Cape of the North Island of New Zealand to depths of about 60 metres, off rocky coasts. Its length is between 15 and 20 cm. Males are highly territorial as they defend their nesting area from other males and other species. These aggressive fish defend their eggs laid by their female counterpart. Spawning occurs between the months of December and March. The New Zealand demoiselle's territory and nesting grounds of this fish are usually the largest in a medium population density. Like most territorial fish they tend to spawn more in higher densities of the same species compared to lower densities. Aggression levels tend to be higher amount higher densities of the same species and lower levels in smaller densities. Aggression also tends to be higher during spawning then during egg defending. Elevated plasma levels of androgen testosterone and 11-Ketotesterone are associated with the heighten levels of aggression shown by the males.
Dascyllus is a genus of fish in the family Pomacentridae. They are usually commensals with corals.
The scissortail sergeant or striptailed damselfish is a large damselfish. It earns its name from the black-striped tail and sides, which are reminiscent of the insignia of a military Sergeant, being similar to those of the sergeant major damselfish. It grows to a length of about 16 centimetres (6.3 in).
The Indo-Pacific sergeant is a species of damselfish in the family Pomacentridae. It may also be known as the Sergeant major although this name is usually reserved for the closely related species Abudefduf saxatilis. The closely related Abudefduf caudobimaculatus was formerly considered to be synonymous with this species and, according to some authorities, is synonymous.
The nosestripe clownfish or nosestripe anemonefish, skunk clownfish, Amphiprion akallopisos, is an anemonefish that lives in association with sea anemones. A. akallopisos is found in the Indian Ocean. It resides in shallow inshore reefs as deep as 15 m with a moderate to strong current. The skunk clownfish can also be kept in captivity by aquarists.
The leopard coral grouper, also known as the common coral trout, leopard coral trout, blue-dotted coral grouper or spotted coral grouper, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in the Western Pacific Ocean.
The green damselfish, also known as the Hawaiian sergeant major, is a non-migratory fish of the family Pomacentridae. This fish also goes by the name maomao It occurs in the Pacific Ocean in the vicinity of the Hawaiian Islands, Midway Island and Johnston Atoll. It can grow to a maximum total length of 30 centimetres (12 in).
Dascyllus albisella commonly known as the Hawaiian dascyllus, Hawaiian domino, Domino damselfish, or white-spotted damsel is a marine fish found in the Eastern Central Pacific.
Dascyllus melanurus, known commonly as the four stripe damselfish, blacktail dascyllus, humbug damselfish, blacktail damselfish, and blacktail humbug, is a species of fish in the family Pomacentridae. It is native to the western Pacific Ocean. It is sometimes kept as an aquarium pet.
Ophioblennius atlanticus, also known as the redlip blenny and the horseface blenny, is a species of combtooth blenny, family Blenniidae, found primarily in the western central Atlantic ocean. Redlip blennies can be found in coral crests and shallow fringing reefs. They are highly territorial and attack intruders with two long, sharp canine teeth. The adults are found at depths of 10 to 20 meters, and the eggs are benthic. The adults may reach up to four inches in length when fully grown, and they have large reddish lips, from which they attained their names. Redlip blennies largely feed on algae.
Dascyllus marginatus is a damselfish endemic to the Western Indian Ocean. It is a site attached fish that lives in corals, usually Stylophora pistillata and species of Acropora. In these corals it hides at a moment of danger and sleeps at night. It feeds on zooplankton that drifts with the current, and grows to a size of 6 cm in length. Dascyllus marginatus lives in groups of 2-25 individuals, and while foraging for food around their home coral, group members keep separated and stable foraging spaces.
The yellowtail damselfish is a species of damselfish native to tropical areas such as the Caribbean coast of Panama. Damselfish are abundant in coral reef environments. The International Union for Conservation of Nature lists this fish as being of “least concern”. The species is exploited on a minor scale, for fisheries and the aquarium trade. It may be threatened by the invasive lionfish.
Dascyllus flavicaudus, common name yellowtail dascyllus, is a Damselfish belonging to the family Pomacentridae.
Abudefduf troschelii, the Pacific sergeant major or Panama sergeant major, is a species of damselfish belonging to the family Pomacentridae that can be identified by the pronounced black stripes on the lateral sides of the fish. Its specific name honors the zoologist Franz Hermann Troschel (1810-1882). It is native to the neritic pelagic zone of the shallow water coral reefs in the Eastern Pacific Ocean and they are an omnivorous species feeding on plankton and algae attached to their coral habitat. Abudefduf troschelii is a sister-species of A. saxatilis but have diverged from each other since the uplift of the isthmus of Panama, separated by the rise of the Panama land bridge 3.1 to 3.5 million years ago. Males, like in many other marine species, take care of and defend newborn A. troschelii after they have been hatched by eggs from the female. There are currently no major threats to the species and there is no indication of a current decline in its population size. The IUCN Red List lists this damselfish as being of “least concern”.
Dascyllus abudafur, the Indian Ocean humbug, is a species of ray-finned fish from the family Pomacentridae, the clownfishes and damselfishes. It is found from the Red Sea, along the coasts of eastern Africa to South Africa, the Seychelles, Comoros, Madagascar and Mascarene Islands east to the Sunda Islands. It has been classified as synonymous with the Pacific humbug Dascyllus aruanus and is not included in FishBase but studies have shown that the two taxa were shown to be genetically and morphologically different. The specific name is derived from the Arabic word for this species Abu-dafur Jabûd.
Plectroglyphidodon dickii, common name blackbar devil, Dick's damsel or narrowbar damselfish, is a species of damselfish in the family Pomacentridae. This species was formerly classified as Dascyllus aruanus, but recently the populations of western Indian Ocean and Pacific Ocean have been split off.