Hyastenus hilgendorfi

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Arthropoda · Class: Malacostraca · Order: Decapoda · Family: Epialtidae · Genus: Hyastenus.

Accepted name: Hyastenus hilgendorfi · Authority: De Man, 1887 · Taxonomic status: accepted · AphiaID: 107324.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=107324 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Hyastenus hilgendorfi. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Depth range: 2–108 m · Habitat zone: benthic.

SeaLifeBase notes: Minimum depth from Ref. 132434. On soft substrate in the subtidal zone (Ref 106854). Found inside epifauna (Ref. 79729). Also occur in coral reefs, the substrate being sandy with corals, shells, and rubble (Ref. 132434).

Source: SeaLifeBase species summary (SpecCode 21152) — https://www.sealifebase.se/summary/Hyastenus-hilgendorfi.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

66 georeferenced occurrence records for Hyastenus hilgendorfi are published through GBIF from 14 countries or marine areas. The map above plots 34 distinct locations from a sample of 66 records, omitting 10 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: Australia (34); Egypt (6); Indonesia (4); Madagascar (4); Papua New Guinea (4); Philippines (4); China (3); Israel (1); India (1); Myanmar (1); Oman (1); Saudi Arabia (1); Thailand (1); United States of America (1).

Marine regions with a valid WoRMS distribution record: European waters (ERMS scope); Red Sea; Mediterranean Sea; Indo-West Pacific; Malay Archipelago; Israeli part of the Mediterranean Sea - Eastern Basin; Suez canal; Levantine Sea; Egyptian part of the Mediterranean Sea - Eastern Basin.

Source: GBIF Occurrence Search (taxonKey 2226742) — https://www.gbif.org/occurrence/search?taxon_key=2226742&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=107324 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Description and natural history (Wikipedia)

Hyastenus hilgendorfi has a roughly pear-shaped carapace which is convex and bearing small tubercles and a downy coat, there is a small epibranchial plug. There are prominent projections on the gastric region, heart and gut. A pair of post-gastric tubercles are close to the orbits. Six mesobranchial tubercles are sub-equal to the sides of the midline.

There are two divergent rostral spines, which have a length of two-thirds of the carapace in males but are much smaller in females. The retractable eyestalks are small. The chelipeds are the same length as the carapace, the merus has nodules in its proximal portion while the claw is smooth and glabrous.

The merus of the pereopods also bear nodules, while the posterior border of the dactyl is spiny, the spines becoming successively larger distally. The separation of the rostral spines is u shaped or keyhole shaped. H. holgendorfi is a brownish colour.

Distribution

Hyastenus hilgendorfi occurs from the Red Sea through the Indian Ocean to the western Pacific to Hawaii and south to Australia. It is reported to occur throughout the Suez Canal and the first record in the Mediterranean was recorded off Israel in 1960. The second record was in 1977 and the third in 2004, which may mean there is a small population in the south eastern Mediterranean.

Biology

Hyastenus hilgendorfi is found on seabeds of coarse sand, debris and gravel, between 2 and 93 metres in depth. It is a "decorator crab" which uses other organisms to cover its body and in a study in the Suez Canal the barnacle Amphibalanus amphitrite, the tunicate Microcosmus sp., and the tube worm Hydroides elegans were found to be the most frequent epibionts. and up to 49 species of epibionts have been recognised for this species in the Suez Canal. The purpose of the decoration in this species seems is to camouflage the crab and disguise its shape.

Source: Wikipedia: Hyastenus hilgendorfi — https://en.wikipedia.org/wiki/Hyastenus_hilgendorfi (CC BY-SA 4.0). Accessed 2026-09-25.