Oldwives

''Enoplosus armatus'', commonly referred to as the old wife (plural: old wives), is a species of centrarchiform ray-finned fish endemic to the temperate coastal waters of Australia. It is the only genus and species in the family Enoplosidae.

It has a deep and compressed body and concave forehead. These features are characteristic of typical butterflyfishes. However, the old wife is easily distinguished by its silver-and-black, vertical, zebra-striped coloration, and by its two prominent dorsal fins. The second dorsal fin is very long and sickle-shaped. The fish grows up to 50 cm long.

Its dorsal fins have bony, knife-like spines.Carl Edmonds, ''Dangerous marine creatures'', 1989. "Although it has been described as venomous, this apparently is of a variable nature as many lacerations from the knife-like dorsal spines have been known by this author to be relatively painless. It appears as if the pain and bleeding may be inversely related, ..." p.70 These have no obvious venom groove nor gland. Nonetheless, the spines are widely considered to inflict a painful venom.

The name "old wife" refers to the sound it makes when caught, caused by it grinding its teeth.Old Wife
The Australian Museum. Other vernacular names have included "bastard dory", "zebra-fish" (also used for ''Girella zebra''), and "double scalare". It has a similar range and appearance to the Moonlighter (''Tilodon sexfasciatus'').

History

The old wife was originally classified in the genus ''Chaetodon'' (with the typical butterflyfishes), but it is now classified as the sole modern species of its own family Enoplosidae and genus ''Enoplosus''. Some fossils have also been added to the genus.

The first description of the species, one of the earliest for any Australian fish, was in 1790 by John White in his ''Journal of a Voyage to New South Wales'' though some sources give George Shaw (who assisted White in the preparation of his manuscript) as the species authority. White originally named it the long-spined chaetodon (''Chætodon armatus'') and described it as follows:

The species was reclassified by Lacépède into its own genus (named from "weapon" in Greek to again reflect the long spines), and was moved by Cuvier from Chaetodontidae into its own separate family within Percoidei.L. Agassiz. 1836. Recherches Sur Les Poissons Fossiles. Tome IV (livr. 6). Imprimerie de Petitpierre, Neuchatel 53-10

/ref>

In 1836, Louis Agassiz, Agassiz identified closely related fossils at Monte Bolca (an important fossil site in Europe) as ''Enoplosus pygopterus'' (named for its smaller fins). These exceptionally well-preserved fossils had a very similar body plan, and even a similar zebra pattern of colouring.The 'Lost Language' of Fishes
(with captione

), Australian Research Council's Centre of Excellence for Coral Reef Studies. Colouring patterns demonstrated to have been preserved in fish (especially old wives) from at least 50 mya. However, more recent studies have recovered this species as actually being an early cardinalfish, moved to its own genus, '' Eosphaeramia''.

References

*
*
*

External links

{{Taxonbar, from=Q162274

Centrarchiformes
Taxa named by John White (surgeon)
Fish described in 1790