''Dascyllus'' is a

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 ...

of fish 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 ...

Pomacentridae Pomacentridae is a family of ray-finned fish, comprising the damselfishes and clownfishes. This family were formerly placed in the order Perciformes or as indeterminate percomorphs, but are now considered basal blenniiforms. They are primaril ...

. They are usually

commensals Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...

with corals.Youtube <> Creatures section, Damselfish - Author:Sublanding Fish 020-06-19/ref>

Taxonomy

Three

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

es have been proposed: the ''D. aruanus'' complex ('' D. aruanus'', '' D. abudafur'', '' D. melanurus''), the ''D. trimaculatus'' complex ('' D. trimaculatus'', '' D. albisella'', '' D. auripinnis'', '' D. strasburgi''), and the ''D. reticulatus'' complex ('' D. reticulatus'', '' D. carneus'', '' D. marginatus'', '' D. flavicaudus''). However, only the ''D. aruanus'' complex and the ''D. trimaculatus'' complex are

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

. The species of the ''D. aruanus'' complex are the most basal in the genus ''Dascyllus.''

Biology

Species of the genus ''Dascyllus'' are found in the

Indo-West Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the s ...

, and are primarily

planktivorous A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and i ...

. The species of the ''D. trimaculatus'' complex are the largest in size, growing up to 90–110 mm ( SL). All other species are smaller, reaching 50–65 mm (SL), with the exception of ''D. flavicaudus'', which reaches 90 mm (SL). Sharm rocks 04

The ''D. trimaculatus'' complex is strongly associated with

sea anemone Sea anemones ( ) are a group of predation, predatory marine invertebrates constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemone ...

s as juveniles. Some and potentially all species in the ''D. trimaculatus'' group are

gonochoristic In biology, gonochorism is a sexual system where there are two sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric. Gonochorism contras ...

, but all other species are

protogynous Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodit ...

(ie, females can change sex and become males as they grow older or larger). It is likely that protogyny arose once in the common ancestor of the genus ''Dascyllus'', which was then lost in the ancestor of the ''D. trimaculatus'' complex. All ''Dascyllus'' species are

demersal The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer o ...

spawners, and in all species, the female lays her eggs in nests prepared by a male, and the eggs are tended by the male until hatching.

Species

Currently, 11 recognized species are placed in this genus:

Trivia

Deb, a character in the

animated film Animation is a filmmaking technique whereby still images are manipulated to create moving images. In traditional animation, images are drawn or painted by hand on transparent celluloid sheets to be photographed and exhibited on film. Animati ...

Finding Nemo ''Finding Nemo'' is a 2003 American animated comedy-drama adventure film produced by Pixar Animation Studios for Walt Disney Pictures. The film was directed by Andrew Stanton, co-directed by Lee Unkrich, and produced by Graham Walters, from ...

'', is a

damselfish Damselfish are those fish within the subfamilies Abudefdufinae, Chrominae, Lepidozyginae, Pomacentrinae, and Stegastinae within the family Pomacentridae. Most species within this group are relatively small, although the four largest speci ...

of genus ''Dascyllus''.Kirkeby, C
What Kind of Creature Is It? Finding Nemo - Cast of Characters.
ClassBrain.com May 22, 2004.

References

Chrominae Marine fish genera Taxa named by Georges Cuvier {{Pomacentridae-stub