Threadfin Anthias

Care at a glance

Overview

A peaceful, active shoaling fish that does best in a group of one male with several females and spends most of the day swimming and picking at plankton in the water column, so it needs multiple small feedings spread through the day rather than one big meal. Rival males will spar with each other, but it otherwise leaves tankmates, corals, and ornamental shrimp alone and is completely reef safe. Good tankmates include other peaceful reef fish, gobies, and dartfish; avoid aggressive or territorial species that will out-compete it for food.

In the wild

Found on coral reef slopes and drop-offs through the western Indian Ocean, typically at 10–30 m, where it hovers in open water over the reef to intercept plankton and retreats into small crevices in the rock when threatened. In the aquarium it needs a lot of open swimming space combined with plenty of small hiding spots in the live rock, strong water movement with a few calmer corners, and subdued rather than bright lighting.

Good to know

A protogynous hermaphrodite that lives in harems of one male with several females; if the male disappears, the largest female converts to male over a period of weeks. The genus name Nemanthias combines the Greek nema, meaning thread or filament, with anthias, a reference to the fine, elongated filaments trailing from the dorsal and tail fins that are most pronounced in males. The species was long classified as Pseudanthias carberryi before being moved into the genus Nemanthias.

Did you know

The threadlike filaments trailing from its dorsal and tail fins, most visible on mature males, are the source of both its common name and its genus name, which translates roughly to thread anthias.

Related species

• 

  Dispar Anthias

  Pseudanthias dispar

  3.7 in (9.5 cm)70 gal (265 L)72–79°F (22–26°C)

• 

  Bartlett's Anthias

  Pseudanthias bartlettorum

  3.5 in (9 cm)70 gal (265 L)72–79°F (22–26°C)

• 

  Evansi Anthias

  Pseudanthias evansi

  4.7 in (12 cm)75 gal (285 L)75–81°F (24–27°C)

• 

  Purple Queen Anthias

  Pseudanthias tuka

  4.7 in (12 cm)75 gal (285 L)75–81°F (24–27°C)

• 

  Chalk Bass

  Serranus tortugarum

  3.1 in (8 cm)29 gal (110 L)72–81°F (22–27°C)
• Randall's Anthias

  Pseudanthias randalli

  3.1 in (8 cm)75 gal (285 L)75–81°F (24–27°C)