Depth
Stylocidaris · Echinoderms (Starfish, Urchins & Brittle Stars)

Red Lance Urchin

Stylocidaris affinis

0-40m
Depth Range
Variable
Max Size
Mediterranean
Distribution
0-40m
Depth Range
Variable
Max Size
Reef & Open
Habitat
Carnivore
Diet
Solitary
Social
LC
IUCN Status
Kingdom Animalia
Phylum Echinodermata
Genus Stylocidaris
Species affinis

Echinoderm

Identification & Biology

  • IdentificationA small sea urchin with a reddish-brown test and a mix of thick, blunt primary spines (banded red and white) and shorter secondary spines. The primary spines are widely spaced, giving it an open, lance-like appearance quite different from densely spined urchins.
  • SizeTest diameter up to 4 cm. A small but distinctive species.
  • Social HabitSolitary or in small groups. Found in crevices and under overhangs during the day. Sometimes collected by divers for aquariums (which should be discouraged).
  • HabitatRocky reefs, caves, and crevices. Prefers shaded environments.
  • Depth5 to 200 m. Common between 10 and 60 m.
  • Feeds OnAlgae, sponges, and encrusting organisms scraped from rock surfaces.
  • DistributionEastern Atlantic and throughout the Mediterranean Sea. Present in Maltese waters.
  • DescriptionStylocidaris affinis is a small but attractive urchin, easily identified by its widely spaced, banded primary spines. It is a cidaroid urchin, belonging to one of the most ancient groups of sea urchins. The thick primary spines are often colonised by encrusting organisms, giving each individual a unique appearance. It is most often encountered in darker recesses and cave environments.

Range

Habitat & Distribution

Found across the Mediterranean, inhabiting reef & open environments. Active from the surface down to 40m depth.

Where Malta divers have spotted this species

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Sightings are logged by divers using our What Did You See? dive-log tool. View the full live sightings map.

Detail

Preferred Environment

Reef & Open habitats, typically at depths of 0-40m. Most commonly encountered by divers at the shallower end of its range.

Encounter Tips

Best approached slowly and calmly. Avoid casting shadows directly over the animal. Neutral buoyancy and patience increase encounter success significantly.

Red Lance Urchin species card

Biology

Behaviour & Diet

Feeding Strategy

Omnivorous grazer feeding primarily on algae and encrusting organisms. Uses its Aristotle's lantern to scrape food from hard rocky surfaces.

Algal grazer

Reproduction

Sexes are separate, with gametes released into the water column during synchronised spawning. Larvae develop through a planktonic pluteus stage.

Broadcast spawner

Behaviour & Defence

Long, densely packed spines present a formidable barrier to predators. The bright red colouration may serve as a warning signal in well-lit shallow habitats.

Spiny armour

Dive with diveshack

Where to Encounter in Malta

The following dive sites offer strong habitat match for Stylocidaris affinis. All are accessible on a guided dive with diveshack.

5-30m
North Malta

Cirkewwa

Rocky reef with caves, arches and ledges hosting a rich diversity of reef species.

View dive site ›
5-50m
Gozo

Blue Hole

One of the Med's most famous reef dive sites. Rocky walls and archways covered in life.

View dive site ›
18-36m
South Malta

Um El Faroud

The wreck lies on a sandy bottom surrounded by rocky reef -- a diverse habitat attracting reef species.

View dive site ›
IUCN Red List Least Concern

Conservation Status

This species is assessed as Least Concern on the IUCN Red List. Mediterranean populations face ongoing pressure from fishing activity, habitat degradation, and climate-driven changes to prey availability.

Source: iNaturalist Guide #888
by Lesley Clements (CC BY-SA)
diveshack Mediterranean Marine Life guide