Johnrandallia nigrirostris
Source: JJPhoto.dk

Facts

Latin name Johnrandallia nigrirostris - (Gill, 1862)
Common name Blacknosed butterflyfish
Family Chaetodontidae - Johnrandallia
Origin East Pacific
Max length 20.0 cm (7.9")

As aquarium fish

Minimum volume 500 l (132 gal)
Hardiness Hardy
Suitable for aquarium Suitable with care
Reef safe Not reef safe
Aggressiveness Mostly peaceful but might be aggressive towards similar species

Food

Maybee
  • Soft coral
Mostly
  • Large polyp stone coral (LPS)
  • Parasites
Recommended
  • Microalgea (Eg. spirulina)
  • Macroalgea (Eg. seaweed / nori)
  • Zooplankton (Cyclops, pods...)
  • Small crustaceans (Krill, mysis, artemia...)
  • Larger crustaceans (Shrimp, crabs...)
  • Other invertebrates

Eats tubeworms

This species likes to eat tubeworms.

Can nibble at clams

This species sometimes nibbles at clams including Tridacna species.

Threat to snails

This species likes eating snails whenever possible.

Frequent feeding

This fish requires feeding several times a day, especially when newly added.

When the fish can find its natural food in the aquarium it requires less frequent feeding. 

Requires a varied diet

This species must be fed with an appropriately varied diet.

Requires plenty of space for swimming.

This species revels in swimming and requires an aquarium with ample space.

Removes parasitic life

This species is able to remove parasites from fish.
It does not have a great impact on a large outbreak of marine ich (Cryptocaryon), for example, but it contributes towards keeping fish parasite free.

Constant cleaning can stress the fish in the aquarium, so one should not add this fish which removes parasites, if the fish are already weakened through other causes.

Not all specimens actively clean fish.

Hiding places

This species needs good hiding places, for example, between live rocks.

Can coexist with its own species

Several specimen of this species can coexist in the same aquarium, provided they are introduced simultaneously.

Family description (Chaetodontidae)

The Butterflyfish are known for their attractive patterns and colours. They are closely related to Angelfishs, but can always be distinguished, as they lack the spines on each side of the head of the Angelfish.

A smaller group of these fish will seek out primairily soft corals, like Zoanthus. A larger part of the species will target different types of LPS corals. Butterflyfish are also known to seek out anemones, tubeworms and bristleworms.

Therefore it is important to choose the correct species in relation to the corals wanted, if one desires to keep Butterflyfish in a coral-aquarium.
Bristleworms, tubeworms and other small invertebrates are also a part of the diet for many Butterflyfish.

It can be problematic, with many of these species, to get them eating in the beginning, but many of the species cannot resist live zooplankton or live mussels with crushed shells. Another option is to mimic their natural behaviour by stuffing their food into coral skeletons or stones.

They ignore most other fish and are generally peaceful, therefore multiple Butterflyfish will have no problem living together. One should however be cautious about keeping similar species together unless they are a couple.

As these fish can be difficult to acclimatize and get feeding, it is important to buy healthy fish, to avoid having to deal with more problems. Make sure to check that they do not have parasites or any visible infections.

There are some species that should not be kept in an a aquarium, as they are food specialists and will almost always refuse to eat replacement foods. It can be possible to breed some species, which will eat frozen foods. Otherwise the only way to keep food specialists is by feeding them their natural diet, which consists of live SPS or LPS corals for example.

FishBase

Aquarium trade Yes
Distribution Eastern Pacific: Gulf of California to Panama, including the Cocos, Malpelo and Galapagos Islands.
English common names Black-nosed butterflyfish
Danish common names Sortsnudet fanefisk

References and further reading

About references

Bob Fenner. El Barbero, Johnrandallia nigrirostris - Wet Web Media - (English)

Scott W. Michael. 2004. Angelfishes and Butterflyfishes (Reef Fishes Series Book 3) TFH Publications / Microcosm Ltd. - (English)
Bob Fenner. Butterflyfishes; Separating the Good Ones and Those You Don't Want - Wet Web Media - (English)
Collection of links to additional information - Wet Web Media - (English)
Tea Yi Kai. 2014. Reef Nuggets 2: Aquatic Lepidopterans for your reef (Revised edition) - Reef Builders - (English)

Froese, R. and D. Pauly. Editors. 2014. FishBase. World Wide Web electronic publication. www.fishbase.org, version (08/2014).

Tags

eats feather duster worm, shoal group, eats tridacna, eats snails, butterfly
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