How to Identify Blacknosed Butterflyfish

To identify Blacknosed Butterflyfish (Johnrandallia nigrirostris), look at these key features.

Physical Characteristics

Body shape

compressed

Coloration

The body is predominantly bright yellow, transitioning to white or silvery-white on the ventral side. A prominent, distinct black band extends from the snout, through the eye, and often fades towards the dorsal fin origin. The dorsal, anal, and caudal fins are typically yellow, sometimes with a darker margin. Juveniles may exhibit a more intense yellow coloration and a more pronounced black band.

Scale type

ctenoid

Mouth position

terminal

Distinctive features

Prominent black snout and eye band, Bright yellow body coloration, Laterally compressed body, Small, brush-like teeth

Dorsal fin

Single dorsal fin with 12-13 spines and 23-25 soft rays. The spiny portion is continuous with the soft-rayed portion.

Tail fin

Truncate to slightly emarginate caudal fin.

Pectoral fin

Well-developed pectoral fins, typically clear to yellowish.

Distinctive fins

Anal fin with 3 spines and 19-21 soft rays. Pelvic fins are small and yellowish.

Identification Tips

1. 1

   Coloration

   Look for the bright yellow body with a distinct black band running from the snout through the eye. The ventral side is typically white or silvery.

2. 2

   Snout

   The prominent black snout is a key identifying feature, giving the fish its common name.

3. 3

   Body Shape

   Its highly compressed, disc-like body is characteristic of butterflyfishes.

4. 4

   Behavior

   Often seen in schools, actively swimming and picking at surfaces or cleaning other fish. This behavior can aid in identification.

Explore Blacknosed Butterflyfish