Tylosurus gavialoides

Stout Longtom
Tylosurus gavialoidesTylosurus gavialoides, NSW, Australia, Photo: Ian Shaw
Tylosurus gavialoidesTylosurus gavialoides, NSW, Australia, Photo: Ian Shaw
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Tylosurus gavialoides
Tylosurus gavialoides




A large and robust longtom, characterised by a wavy tail margin that has a noticeably longer lower than upper lobe. Endemic to tropical and subtropical Australia, and very easily confused with T. crocodilus in the field, which also occurs in Australia (but is more widespread). Similar Strongylura incisa has a flatter tail margin.


Max Size: 75 cm

Sea Temperature Range: 17.5-22.8°C

Depth: N/A

Habitat Generalization Index: N/A

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.

Conservation and Rarity

IUCN Status: Not Evaluated

Occurrence: Infrequent (1.8% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Several (8 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.