Lamarck's Angel (Genicanthus lamarck) Care Guide
Genicanthus lamarck is a planktivorous swallowtail angelfish from the Indo-West Pacific, known for sexual dichromatism and reef-safe feeding habits.
Compiled by Aquairi from published sources · Published · Updated
Overview
Genicanthus lamarck is a swallowtail angelfish of the family Pomacanthidae. FishBase records a maximum length of about 25.0 cm. Like other Genicanthus species it is sexually dichromatic, with males and females differing in pattern, and it feeds in midwater rather than grazing reef surfaces.
Taxonomy
- Family: Pomacanthidae
- Genus: Genicanthus
- Scientific name: Genicanthus lamarck
Habitat
FishBase reports an Indo-West Pacific range from the Indo-Malayan area east to Vanuatu, north to southern Japan and south to the Great Barrier Reef. It is marine, reef-associated and non-migratory, inhabiting shallow reef crests and deep reefs adjacent to steep slopes at depths of about 10-50 m.
Tank requirements
- Minimum tank volume: 600 L (159 gal)
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- dKH (carbonate hardness): 8-12
- Lifespan: 10-15 years
Diet
FishBase reports that the species feeds on plankton, forming aggregations to feed in midwater well above the bottom. In aquaria it accepts frequent small feedings of meaty planktonic foods such as mysis and enriched brine shrimp.
Compatibility
It is a peaceful, mid-water angel. FishBase notes that it forms harems of 3-7 individuals. Suitable companions include tangs, wrasses, anthias and clownfish, while aggressive large Pomacanthus angels are best avoided.
Reef compatibility
Because it feeds on plankton in open water, Genicanthus lamarck is regarded as reef-safe and generally ignores corals. Maintain specific gravity around 1.024-1.026 and carbonate hardness of 8-12 dKH.
Conservation status
IUCN Red List: Least Concern (assessed 2009), as reported by FishBase.
Genicanthus lamarck (Lamarck's Angel) Breeding Guide
Overview
Genicanthus lamarck is a swallowtail angelfish of the Indo-West Pacific, from the Malayan region east to Vanuatu, north to southern Japan and south to the Great Barrier Reef. It reaches about 25 cm at depths of roughly 10 to 50 m, feeding on plankton in midwater. Unlike most angelfish it ignores corals and sessile invertebrates, making the genus reef-safe. Genicanthus are regarded as the most breedable angels, though captive offspring remain a specialist achievement.
Sexing
Genicanthus is the only sexually dichromatic angelfish genus, so the sexes are easily told apart. In G. lamarck males show a yellow crown patch, black pelvic fins and elongated caudal lobes, while females have white pectoral fins and black caudal lobes. It is a protogynous hermaphrodite: if the male in a harem disappears, the dominant female changes sex to male.
Spawning Behavior & Trigger
In the wild G. lamarck lives in small harems of a dominant male with two to six females, forming feeding aggregations in midwater. Swallowtail angels are pair-spawners: as in other pomacanthids, courtship intensifies toward dusk, when a female rises into the water column with the male and releases buoyant pelagic eggs at the peak of the ascent.
Egg & Fry Care
Genicanthus produce extremely small pelagic eggs that hatch into equally minute prolarvae. Standard rotifers are too large for the first-feeding mouth, so successful rearing in related species has relied on cultured copepods and other tiny live prey. There is no parental care; raising the larvae, rather than achieving spawning, is the central difficulty.
Common Challenges
- Pelagic eggs disperse on release and cannot be collected from a display.
- Prolarvae are too small for rotifers and need cultured copepods.
- A breeding pair needs a very large reef system, given the adult size.
- No captive rearing of this particular species has been documented.