Saltwater Aquarist

Lamarck's Angelfish

(Genicanthus Iamarck)

Lamarck's Angelfish

Species Description…

Scientific Name: Genicanthus Iamarck
Common Name: Lamarck's Angelfish
Species Group: Angelfish
Habitat: Reef Safe
Care Level: Intermediate
Temperament: Peaceful
Diet Type: Omnivore
Role in Aquarium: Showpiece Fish
Max Fish Length: 8 (inches)
Min Aquarium Size: 125 (gallons)
Native Range: Indo-Pacific

Overview

  • Native to the Indo-Pacific, commonly found in deep reef slopes and lagoons.
  • Recognized for its elegant silver body with black horizontal stripes.
  • A sexually dimorphic species, with females appearing more vibrant than males.
  • Unlike many angelfish, it is planktonic rather than grazing on coral reefs.
  • A peaceful species that adapts well to community aquariums.

Feeding

  • Primarily feeds on zooplankton and suspended particles in the water column.
  • Readily consumes high-quality flakes, pellets, frozen mysis shrimp, and brine shrimp.
  • Should be fed multiple small meals daily to mimic natural feeding habits.
  • Can benefit from occasional supplementation with marine algae.
  • Best kept in a tank with strong water circulation to help simulate natural feeding conditions.

Habitat

  • Commonly inhabits depths of 30-100 feet on outer reef slopes.
  • Requires an aquarium with open swimming space and moderate water flow.
  • Best kept in a tank with rock structures for shelter and territories.
  • Reef-safe, as it does not nip at corals, unlike other angelfish species.
  • Ideal for large, well-established aquariums (minimum 100 gallons).

Fish Care

  • Optimal water temperature: 74-80°F (23-27°C).
  • Ideal pH range: 8.1-8.4, with a specific gravity of 1.023-1.026.
  • Requires a well-maintained tank with stable water conditions.
  • Highly resistant to disease when provided with a proper diet and environment.
  • Can be sensitive to poor water quality, requiring regular maintenance.

Compatibility

  • One of the most peaceful angelfish, suitable for community reef tanks.
  • Compatible with tangs, wrasses, gobies, and other non-aggressive species.
  • Best kept singly or in a bonded male-female pair to avoid territorial disputes.
  • Avoid housing with overly aggressive tank mates that may stress it.
  • Can coexist with larger, peaceful angelfish if the tank is spacious enough.

Aquarium Behavior

  • Active swimmer, often found patrolling the mid-to-upper water column.
  • Social and interactive, making it a beautiful centerpiece fish.
  • Adapts quickly to aquarium life and becomes more confident over time.
  • Exhibits minimal aggression, making it a great choice for mixed reef setups.
  • Thrives in an environment with high oxygenation and moderate current flow.