The immaculate damselfish (''Mecaenichthys immaculatus''), also known as the green puller, is a species of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

, it is the only species in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Mecaenichthys'', classified in the subfamily

Pomacentrinae Pomacentrinae is one of four subfamilies in the family Pomacentridae which includes the clownfishes and the damselfishes. It is the most diverse of the subfamilies in the Pomacentridae with around 21 genera and approximately 200 species. Chara ...

of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Pomacentridae. The immaculate damselfish is distinguished from other species of

damselfish Damselfish are those within the subfamilies Abudefdufinae, Chrominae, Lepidozyginae, Pomacentrinae, and Stegastenae within the family Pomacentridae. Most species within this group are relatively small, with the largest species being about ...

es by having a pointed head with large eyes and bluish-silver coloured body with a thin blue iridescent margin around the

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

. The juveniles are orange in colour with bright blue iridescent stripes. The juveniles are similar to juveniles of the damselfish of the genus ''

Parma Parma (; egl, Pärma, ) is a city in the northern Italian region of Emilia-Romagna known for its architecture, music, art, prosciutto (ham), cheese and surrounding countryside. With a population of 198,292 inhabitants, Parma is the second mos ...

''. This species grows to . The Immaculate damselfish is endemic to Australia where it is known from marine waters of southern

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

to southern

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

. The species is found in depths of . The adults are found on rocky or weedy inshore reefs and form pairs during breeding. Their eggs are demersal and adhere to the substrate where they are guarded and aerated by the male.

References

Pomacentrinae Mecaenichthys Mecaenichthys immaculatus {{Pomacentridae-stub