''Taiaroa'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of deep-water, solitary marine

octocorals Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising around 3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fan ...

in the

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

Taiaroidae. ''Taiaroa'' is

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 "unispec ...

in the family Taiaroidae and contains a single

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, ''Taiaroa tauhou''. The species was first described by the marine zoologists Frederick M. Bayer and Katherine Margaret Muzik in 1976. The scientific name derives from "Taiaroa", the submarine canyon off New Zealand in which the first specimens were found and "tauhou", the Maori word for "strange".

Taxonomy

In 1973, a new species of solitary octocoral was dredged from the seabed off the

Otago Peninsula The Otago Peninsula ( mi, Muaūpoko) is a long, hilly indented finger of land that forms the easternmost part of Dunedin, New Zealand. Volcanic in origin, it forms one wall of the eroded valley that now forms Otago Harbour. The peninsula lies sou ...

, New Zealand, at a depth of . At first it was believed to be a species of burrowing

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

and it was given to marine biologist Dr. Cadet Hand for examination. He quickly realised it was an octocoral and sought the assistance of marine biologist Dr Frederick Bayer, who gave it the name ''Taiaroa tauhou''. In 1976, the suborder Protoalcyonaria was re-established to accommodate it and further specimens which had been discovered. This higher-level taxon had been erected by Sydney Hickson in 1894 for non-colonial octocorals. However, there was doubt whether these were really solitary, or whether they were just the young forms of colonial species, and it became redundant when the genera included in it were all transferred to other taxa. In 2022 the species was reclassified as a member of the newly erected order Malacalcyonacea.

Description

''Taiaroa tauhou'' has a tall, cylindrical body held in place in soft substrate by numerous filaments attached to the base. The anthocodia, the upper part of the polyp bearing the eight pinnate tentacles and the mouth, can be fully retracted back into the anthostele, the rigid, lower part of the polyp. The anthostele is strengthened by spindle-shaped calcareous

sclerite A sclerite (Greek , ', meaning "hard") is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly ...

s and has eight longitudinal ridges. It comprises more than half of the polyp's length. The largest individual examined had a total length of and a maximum diameter of . The retractible anthocodia measured . The body wall is opaque and beige in colour. The filaments securing the polyp to the substrate are encrusted with sediment.

Biology

''Taiaroa tauhou'' is a solitary coral that reproduces solely by means of sexual reproduction. It may be a

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

, as one individual examined contained both eggs and spermaries (sperm producing organs), but other individuals only contained eggs or were exclusively male. It is unclear whether the gonads in the bisexual individual were attached to the body wall. It may be that the males liberate spermaries which are ingested by the females, resulting in internal fertilisation, and this would mean that the animals are not hermaphroditic.

References

{{Taxonbar, from1=Q2763392, from2=Q18518908, from3=Q10377837 Protoalcyonaria Invertebrates of New Zealand Animals described in 1976