Leptomithrax australis
Source-cited species reference: taxonomy from WoRMS, biology from SeaLifeBase, occurrence map from GBIF, description from Wikipedia.
Leptomithrax australis, or the giant masking crab, is a species of spider crab in the genus Leptomithrax. It has been found in the Southwest Pacific region. It lives both shallow and deep waters, with a zone depth of 550 m.
- Scientific name
- Leptomithrax australis
- Authority
- (Jacquinot in Jacquinot & Lucas, 1853)
- Family
- Majidae
- Order
- Decapoda
- Habitat zone
- benthic
- Gbif occurrence records
- 244
Classification (WoRMS)
Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Arthropoda · Class: Malacostraca · Order: Decapoda · Family: Majidae · Genus: Leptomithrax.
Accepted name: Leptomithrax australis · Authority: (Jacquinot in Jacquinot & Lucas, 1853) · Taxonomic status: accepted · AphiaID: 442007.
Synonyms and superseded combinations recorded for this taxon: Maia australis Jacquinot in Jacquinot & Lucas, 1853; Paramithrax (Leptomithrax) brevirostris Miers, 1879.
Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=442007 (CC BY 4.0). Accessed 2026-09-23.
Biology and life history (SeaLifeBase)
Measured values published by SeaLifeBase for Leptomithrax australis. 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 130863) — https://www.sealifebase.se/summary/Leptomithrax-australis.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.
Distribution and occurrence records (GBIF)
244 georeferenced occurrence records for Leptomithrax australis are published through GBIF from 1 countries or marine areas. The map above plots 128 distinct locations from a sample of 244 records; it shows where the species has been observed and reported, not a modelled range.
Most records by country or area: New Zealand (243).
Marine regions with a valid WoRMS distribution record: New Zealand Exclusive Economic Zone.
Source: GBIF Occurrence Search (taxonKey 2226551) — https://www.gbif.org/occurrence/search?taxon_key=2226551&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=442007 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.
Description and natural history (Wikipedia)
It has a pyriform carapace and elongated walking legs. The carapace demonstrates moderate convexity with well-defined regions separated by distinct grooves. Unlike some congeners, L. australis presents a less pronounced pear shape compared to species like L. longimanus, appearing more oval in overall outline. It reaches up to 90 mm long and females up to 60 mm. The carapace of L. australis displays numerous tubercles and spines. The rostral region features two short, stout spines that are characteristic of the species. The hepatic margin typically bears two widely spaced spines, while the branchial margin supports four prominent conical spines with several smaller spines or tubercles positioned between them.
The dorsal surface exhibits extensive tuberculation, with rows of tubercles extending posteriorly from the rostral base along each side of the midline. This tuberculate pattern continues at least to the level of the postorbital region, contributing to the species' distinctive appearance.
Comprehensive biogeographic databases indicate the presence of L. australis in New Zealand waters, where it represents part of a diverse spider crab fauna. The New Zealand region supports multiple Leptomithrax species, reflecting the area's importance as a center of diversity for this genus.
Source: Wikipedia: Leptomithrax australis — https://en.wikipedia.org/wiki/Leptomithrax_australis (CC BY-SA 4.0). Accessed 2026-09-23.
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