Dusky rabbitfish
Siganus fuscescens
Also known as Mottled Spinefoot, Black Rabbitfish, Happy Moments, Fuscous Rabbitfish
SaltwaterFish
Care at a glance
- Temperature
- 72–79°F
- 22–26°C
- pH
- 8.1–8.4
- Adult size
- 15.7 in
- 40 cm
- Minimum tank
- 120 gal
- 454 L
- Temperament
- Peaceful
- Social behavior
- Solitary
- Swim level
- Middle
- Diet
- Herbivore
- Difficulty
- Easy
- Breeding
- Hard
- Rarity
- Common
- Reef safe
- Reef safe with caution
- Family
- Siganidae
- Origin
- Western Pacific, Japan to Australia
Overview
The dusky rabbitfish is a peaceful, hard-working algae grazer for a large saltwater system. It is an easy fish to keep.
Did you know
The dusky rabbitfish goes by the nickname happy moments in Australia. It is a dry reference to how it feels to grab one of its venomous spines by mistake.
Caring for the dusky rabbitfish
A full-grown dusky rabbitfish needs a long tank of at least 120 gal (454 L), with real swimming room. Keep the water at 72 to 79°F (22 to 26°C), with a pH of 8.1 to 8.4.
It spends the day cropping filamentous and leafy algae, which makes it good natural algae control in a large system. Captive-bred fish accept pellets, frozen foods and nori readily.
The dusky rabbitfish is peaceful and safe with community fish. Treat it as reef safe with caution. A puncture from its spines is painful, so keep your hands slow around the tank and the net. Breeding it is hard.
Good to know
The dusky rabbitfish, like all rabbitfish, has dorsal, pelvic and anal spines backed by venom glands. Most adults settle in around the mid 20s in centimeters, short of the top size.
In the wild
The dusky rabbitfish ranges across the western Pacific, from southern Korea and Japan down to Australia. It grazes algal flats, seagrass meadows and shallow lagoon and coastal reefs. It is usually met as a school working across the bottom, rather than as a lone fish.
Weekly picks
Tank mates
The dusky rabbitfish is a peaceful, solitary 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.
Skunk cleaner shrimp
Lysmata amboinensis
Saltwater2.4 in (6 cm) · 20 gal (75 L)73–81°F (23–27°C)
Tiger / strawberry conch
Conomurex luhuanus
Saltwater2.8 in (7 cm) · 20 gal (75 L)75–81°F (24–27°C)
Gold-specs jawfish
Opistognathus randalli
Saltwater3.9 in (10 cm) · 30 gal (115 L)73–81°F (23–27°C)
Lyretail anthias
Pseudanthias squamipinnis
Saltwater5.1 in (13 cm) · 129 gal (490 L)75–81°F (24–27°C)
Fire shrimp
Lysmata debelius
Saltwater2.4 in (6 cm) · 20 gal (75 L)72–79°F (22–26°C)
Ring cowrie
Monetaria annulus
Saltwater1.2 in (3 cm) · 20 gal (75 L)75–81°F (24–27°C)
Common questions
What size tank does a dusky rabbitfish need?
A dusky rabbitfish needs at least 120 gal (454 L). It spends most of its time in the middle.
What temperature and pH does a dusky rabbitfish need?
A dusky rabbitfish is comfortable at 72–79°F (22–26°C) with a pH of 8.1–8.4.
What does a dusky rabbitfish eat?
A dusky rabbitfish spends the day cropping filamentous and leafy algae. Captive-bred fish readily accept pellets, frozen foods and nori.
How big does a dusky rabbitfish get?
An adult dusky rabbitfish reaches about 15.7 in (40 cm).
Related species
16.9 in (43 cm)125 gal (473 L)72–79°F (22–26°C)Goldline rabbitfish
Siganus lineatus
16.9 in (43 cm) · 125 gal (473 L)
11.8 in (30 cm)119 gal (450 L)75–81°F (24–27°C)Two-barred rabbitfish
Siganus virgatus
11.8 in (30 cm) · 119 gal (450 L)
9.8 in (25 cm)106 gal (400 L)75–81°F (24–27°C)Barred rabbitfish
Siganus doliatus
9.8 in (25 cm) · 106 gal (400 L)
9.4 in (24 cm)124 gal (470 L)75–81°F (24–27°C)Bicolor foxface
Siganus uspi
9.4 in (24 cm) · 124 gal (470 L)
9.4 in (24 cm)124 gal (470 L)72–79°F (22–26°C)Foxface rabbitfish
Siganus vulpinus
9.4 in (24 cm) · 124 gal (470 L)
9.1 in (23 cm)124 gal (470 L)75–81°F (24–27°C)Magnificent foxface
Siganus magnificus
9.1 in (23 cm) · 124 gal (470 L)