Abatus cordatus
Source-cited species reference: taxonomy from WoRMS, biology from SeaLifeBase, occurrence map from GBIF, description from Wikipedia.
Last updated
Kathryn Deneroff · via Wikipedia: Abatus cordatus · CC0
Abatus cordatus is a species of sea urchin in the family Schizasteridae. It is native to shallow seas surrounding certain island groups in the southern Indian Ocean.
The body is protected by a hard test or shell which is covered with spines. The female broods its young in deep pockets on the upper surface, retaining the young in place with specialised spines. American zoologist Addison Emery Verrill first scientifically described A. cordatus in 1876.
Scientific classification
- KingdomAnimalia
- PhylumEchinodermata
- ClassEchinoidea
- OrderSpatangoida
- FamilySchizasteridae
- GenusAbatus
- SpeciesAbatus cordatus
Named by (Verrill, 1876)
Sources: Wikipedia taxobox: Abatus cordatus (CC BY-SA 4.0) · order, family and genus agree with WoRMS AphiaID 160763 (CC BY 4.0)
Where the abatus cordatus has been recorded
Each dot is a place where the species has been observed and reported (523 records, half-degree grid) — not a modelled range. 8 inland records left out (institution coordinates). 1 isolated far-off record not drawn.
Map: drawn by Codexery. Data: GBIF occurrence search (records CC0 / CC BY) · Natural Earth basemap (public domain) · place coordinates: Wikipedia (CC BY-SA 4.0)
Quick Facts
- Authority
- (Verrill, 1876)
- Family
- Schizasteridae
- Order
- Spatangoida
- Habitat zone
- benthic
- Gbif occurrence records
- 523
Facts from the source article.
Classification (WoRMS)
Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Echinodermata · Class: Echinoidea · Order: Spatangoida · Family: Schizasteridae · Genus: Abatus.
Accepted name: Abatus cordatus · Authority: (Verrill, 1876) · Taxonomic status: accepted · AphiaID: 160763.
Synonyms and superseded combinations recorded for this taxon: Hemiaster cordatus Verrill, 1876.
Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=160763 (CC BY 4.0). Accessed 2026-09-25.
Biology and life history (SeaLifeBase)
Measured values published by SeaLifeBase for Abatus cordatus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.
Habitat zone: benthic · Aquarium trade: never/rarely.
Source: SeaLifeBase species summary (SpecCode 152250) — https://www.sealifebase.se/summary/Abatus-cordatus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.
Distribution and occurrence records (GBIF)
523 georeferenced occurrence records for Abatus cordatus are published through GBIF from 4 countries or marine areas. The map above plots 20 distinct locations from a sample of 523 records, omitting 8 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.
Most records by country or area: French Southern Territories (495); Heard Island and McDonald Islands (24); Bouvet Island (3); France (1).
Marine regions with a valid WoRMS distribution record: Kerguelen Exclusive Economic Zone; Antarctic Ocean; Heard and McDonald Islands Exclusive Economic Zone; Heard and Macdonald Islands; Kerguelen Islands.
Source: GBIF Occurrence Search (taxonKey 5721199) — https://www.gbif.org/occurrence/search?taxon_key=5721199&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=160763 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.
Description and natural history (Wikipedia)
The test of this species is oval and bilaterally symmetrical, up to 5 cm long. The oral (under) surface is relatively flat but the aboral (upper) surface is domed, the colour being some shade of yellowish or greenish-brown. The test is thin and fragile, and is entirely covered with spines of various lengths in different parts.
The anterior ambulacrum forms a shallow depression and the other four ambulacra form a star-shaped furrow across the surface of the test; this is shallow in males, but much deeper in females, forming pockets in which the young are incubated. The pockets are protected by specialized spines. On the oral surface the spines are short and used for locomotion, while the surrounding spines are used for digging.
Distribution and habitat
Abatus cordatus is endemic to certain subantarctic island groups in the southern Indian Ocean. It is known from the Kerguelen Islands, and the Heard Island and McDonald Islands. It occurs buried in soft muddy or sandy sediment, usually at depths down to about 2 m, but has been found at depths as great as 560 m.
Ecology
This sea urchin is a detritivore and feeds on organic matter in the sediment. It is gonochoric, individuals being either male or female. The eggs are large and yolky, and when they have emerged from the female's gonopore, they fall into the adjacent pockets; here they undergo direct development, being brooded for about nine months, with a few dozen young in each pocket. By this time they have developed into juveniles about 2 mm in diameter with mouths and spines.
They then crawl away from their mother. This is the first time that direct development has been observed among sea urchins. It is not clear precisely when the eggs are fertilised, but it has been discovered that the juveniles do not necessarily all share the same father.
Because of the absence of a larval stage, most juveniles do not disperse more than a few metres from their parent. They have no known predators, and under favourable conditions can be very numerous, with up to 200 per square metre having been recorded. Their lack of ability to disperse may make them sensitive to alterations in their habitat such as changes in seawater temperatures.
Source: Wikipedia: Abatus cordatus — https://en.wikipedia.org/wiki/Abatus_cordatus (CC BY-SA 4.0). Accessed 2026-09-25.
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Abatus cordatus (CC BY-SA 4.0).
- Classification: the source article's taxobox; order, family and genus checked against WoRMS, the World Register of Marine Species (CC BY 4.0).
- Occurrence records: GBIF (CC0 / CC BY). Basemap: Natural Earth (public domain).
- Biology values: SeaLifeBase species summary (CC BY-NC 3.0, non-commercial).
- Word definitions: the , each quoted from its Wikipedia article.
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