TankBud

McCosker's flasher wrasse

Paracheilinus mccoskeri

Also known as McCosker's Wrasse, McCosker Wrasse

SaltwaterFish

McCosker's flasher wrasse (Paracheilinus mccoskeri)
jeyre · CC BY 4.0

Care at a glance

Temperature
72–79°F
22–26°C
pH
8.1–8.4
Adult size
3.1 in
8 cm
Minimum tank
55 gal
208 L
Temperament
Peaceful
Social behavior
Social
Swim level
Middle
Diet
Carnivore
Difficulty
Easy
Breeding
Hard
Rarity
Common
Reef safe
Reef safe
Family
Labridae
Origin
Indo-Pacific reefs, from the western Indian Ocean to Fiji

Overview

McCosker's flasher wrasse is a peaceful zooplankton eater that hovers in the open water of a reef tank. It is easy to keep.

Did you know

The flashing that names the McCosker's flasher wrasse is a real courtship move. The male spreads his dorsal and anal fins fully and pulses through his brightest colors in quick bursts while darting around a female. Each display lasts only seconds but repeats over and over around dawn and dusk.

Caring for the McCosker's flasher wrasse

Give a McCosker's flasher wrasse at least 55 gal (208 L) of mostly open swimming space above live rock. It spends most of the day hovering and displaying rather than perching on the rockwork. Like all flasher and fairy wrasses, it is a strong, accurate jumper, so seal the lid completely.

Keep the water at 72 to 79°F (22 to 26°C) with a pH of 8.1 to 8.4. It picks zooplankton from the water column, so feed enriched mysis, brine shrimp and other small meaty foods several times a day.

McCosker's flasher wrasse is peaceful and completely reef safe, and it does not bother corals or invertebrates. Keep a single male, ideally with two or three females. Males spar with rival males of their own or similar flasher wrasse species.

The male has an orange-red body with iridescent blue horizontal stripes and a yellow belly. The first ray of his dorsal fin is elongated and used in display. Females and juveniles stay a duller orange, with faint purple lines near the head. Breeding McCosker's flasher wrasses is hard.

Good to know

Paracheilinus mccoskeri is a protogynous hermaphrodite in the wrasse family Labridae. Like several other reef wrasses, it sleeps wrapped in a self-secreted mucous cocoon at night.

In the wild

McCosker's flasher wrasse lives over outer reef slopes, rubble and algae beds from the western Indian Ocean to Fiji. It is found at depths of 5 to 50 m.

Weekly picks

Tank mates

The McCosker's flasher wrasse is a peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a McCosker's flasher wrasse need?

A McCosker's flasher wrasse needs at least 55 gal (208 L). It spends most of its time in the middle.

What temperature and pH does a McCosker's flasher wrasse need?

A McCosker's flasher wrasse is comfortable at 72–79°F (22–26°C) with a pH of 8.1–8.4.

What does a McCosker's flasher wrasse eat?

A McCosker's flasher wrasse picks zooplankton from the water column. Feed it enriched mysis, brine shrimp and other small meaty foods several times a day.

How big does a McCosker's flasher wrasse get?

An adult McCosker's flasher wrasse reaches about 3.1 in (8 cm).

How can you tell a male McCosker's flasher wrasse from a female?

Males have an orange-red body with iridescent blue horizontal stripes, a yellow belly and an elongated first ray on the dorsal fin. Females stay a duller orange, with faint purple lines near the head.

Related species