Red Sea Toby

Canthigaster margaritata (Rüppell, 1829)

syn. Canthigaster margaritatus, Tetraodon margaritatus

up to 11.5 cm1-30 mRed Sea endemicPoisonousLeast Concern

1256

A small sharp-nosed puffer, barely 11.5 cm (4.5 in), brown above with dense pale blue spots and orange lines radiating from the eye. It lives here and in the 🌊 Gulf of Aden and nowhere else, replacing the same-shaped tobies that occupy the rest of the Indo-Pacific.

Size is deceptive. Tobies are pufferfish, carrying the same tetrodotoxin as their large relatives in skin and organs, and they are also unusual in secreting it into the skin mucus - so a fish this small is left alone by predators that could swallow it whole without noticing.

A male holds a small territory containing several females and patrols it all day, driving off other males. Spawning is done in an algae tuft on the bottom: the female lays a small clutch in the algae and neither parent guards it afterward, which is unusual for a fish this territorial.

It feeds on almost anything small and slow - algae, sponges, tunicates, worms, small crustaceans - by nipping with four fused teeth, and a toby working over a coral head is one of the more watchable small fish on a shallow dive.

The genus. Canthigaster Swainson 1839 - [a]canthus (thorn or spine) + gaster (belly). ETYFish

The species. Canthigaster margaritata (Rüppell 1829) - adorned with pearls. ETYFish

How to recognise it

small pointed-snouted puffer, brown above with dense pale blue spots
orange-brown lines radiating from the eye
sharp keel along the belly and a small pointed tail, held closed
length up to 11.5 cm

Why it's threatened

Residential & commercial development

Housing & urban areas · Commercial & industrial areas · Tourism & recreation areas

Biological resource use

Intentional use: (subsistence/small scale) [harvest]

Pollution

Sewage · Run-off · Type Unknown/Unrecorded · Oil spills · Seepage from mining · Nutrient loads · Soil erosion, sedimentation · Herbicides and pesticides · Garbage & solid waste

Climate change & severe weather

Habitat shifting & alteration · Temperature extremes

Although C. margaritata appears to be abundant and widespread, it may be experiencing localized population declines as a result of habitat loss in parts of its range.

As of 2008, fifteen percent of the world’s coral reefs were considered under imminent threat of being “Effectively Lost” (with 90% of the corals lost and unlikely to recover soon), with regions in East Africa, South and South-east Asia, and the wider Caribbean being the most highly threatened (Wilkinson et al. 2008). In the Red Sea, which includes 17640 km2 of coral reef area, 4% of the reefs have been effectively lost (90% mortality), while another 4% are at a critical stage with 50-90% loss of coral cover as of 2008 (Wilkinson et al. 2008).

Of 704 zooxanthellate reef-building coral species which were assessed by using the International Union for Conservation of Nature Red List Criteria, 32.8% are in categories with elevated risk of extinction (Carpenter et al. 2008).

This species is a component of the international marine aquarium trade. The effect of this trade on the population of C. margaritata.

Threat classification from the IUCN Red List.