38 photos - 20 species


 Their rostrum is as long as the carapace or slightly longer.

It is pointed and spiny and can cause painful injuries.

The legs are very long and give the crabs a spider-like appearance.

Male spider crabs are considerably smaller than females.

Achaeus spinosus

Spiny spider crab or Electric crab

 Maximum length: 4 cm

Legs and body are bristly, two pointed spines between the eyes.

Its body is white and its eyes red.

Lives on soft corals and is nocturnal.

Many species camouflage themselves by attaching organisms to their body

that remain attached to their bristles.

Photos 1 - 2 Johnny: Hurghada Egypt

Achaeus sp.

Achaeus sp. nothing known yet

 Maximum length: ? 

Unfortunately nothing is known about this species.

Photo 1 Johnny: Bangka Island North Sulawesi

Amphithrax aculeatus

Paved clinging crab or Mithracid spider crab

 Depth: 0 - 100 m

Unfortunately there is nothing worth mentioning about this species on the net,

except that it can be found down to a depth of 100 metres.

I was kindly given the name of the animal by Ron Silver from the USA.

Photo 1 Johnny: Bonaire Caribbean

Amphithrax hemphilli

Spider crab

 Maximum size: 32 mm

Maximum depth: 1 - 60 m

It is a fairly common species in its area of distribution

and can be found from the shallow intertidal zone to a depth of 60 metres.

Lives in various habitats: sea grasses, coral and rock reefs, dead corals, calcareous algae,

sand reefs, as well as in coral and limestone rubble.

Photo 1 Johnny: Bonaire Caribbean

Chalaroachaeus curvipes

Curly spider crab or Speckled goodness

 Maximum length: 3 cm

Whitish-transparent body with dark spots.

Camouflages with moss animals.

Photo 1 Johnny: Bangka Island North Sulawesi

Camposcia retusa

Decorator crab

 Maximum length: 5 cm

The body and legs are completely covered with various sea creatures or algae,

only the black eyes are visible.

Moves very slowly.


Photos 1 - 2 Johnny: Bangka Island North - Sulawesi

Photo 3 Johnny: Bali Indonesia

Epialtidae sp

possibily hydroid spider crab

Maximum length: ?

The following text is from a friend of reeflexicon.

Such animals can hardly ever be identified on the basis of a photo.

They are simply too heavily camouflaged with everything possible.

No body structure / special features can be seen.

What is certain is that it is a spider crab, family Epialtidae,

most likely a Hyastenus sp. - Hydroid spider crab.

Possible and relatively frequently documented are e.g.

Hyastenus bispinosus

Hyastenus borradailei

Other species are also possible, such as Lahaina ovatus....

She is great at identifying marine animals, but here she reached her limits.

I have now set it like this. Thanks a lot to you

Photo 1 Johnny: Bangka Island North Sulawesi

Hoplophrys oatesi

Soft coral crab, Candy crab or Dendronephtya crab

 Maximum length: 2 cm

Hides between polyps of soft corals.

The body colour ranges from white, yellow to red or pink,

depending on the colour of its host coral.

The crab camouflages itself by attaching soft coral polyps to and on its carapace.

There are small claws on the first pair of legs and larger spines on the body,

which are translucent with a red and white pattern.

Photo 1 Astrid: Lembeh Strait North - Sulawesi

Photo 2 Johnny: Lembeh Strait North - Sulawesi

Huenia heraldica

Halimeda crab or Arrowhead crab

 Maximum length: 3 cm

This species looks like a Halimeda alga and is therefore very well camouflaged against its predators.

Photos 1 - 2 Johnny: Bangka Island North Sulawesi

Hyastenus sp. 1

Hyastenus sp nothing known yet

 Maximum size: 3 cm

The first pair of legs has small claws.

Two long pointed eye spines and a blunt spine at the rear end of the carapace.

Likes to camouflage itself with hydroid polyps and detritus.

Photos 1 - 2 Johnny: Hurghada Egypt

Macrocoeloma trispinosum

Sponge decorator crab

 Maximum depth: 20 metres

These crabs are characterised by their amazing ability to camouflage themselves with organisms

in their environment such as corals, anemones, sponges and various algae.

Photo 1 Johnny: Lembeh Strait North - Sulawesi

Photo 2 Johnny : Bangka Island North - Sulawesi

Maguimithrax spinosissimus

West indian spider crab, Channel clinging crab, Reef spider crab,

Spiny spider crab or Coral crab

 Maximum size: 18 cm

The carapace and legs are reddish to brown, purple-grey smooth claws and they have

a row of knots on the outer edge.

They have short spines and knots on their legs and the tips of their claws are blunt.

They live in caves or overhangs during the day and forage at night.

It is the largest reef crab in the Caribbean.

Not shy, allows divers to get close to it.

Photos 1 - 2 Johnny: Bonaire Caribbean

Photos 3 - 4 Astrid: Bonaire Caribbean

Mithraculus forceps

Red-ridged clinging crab


 Maximale Größe: 3 - 5 cm

Tiefe: 0 - 90 m

Klumpiger heller bis dunkelrotbrauner Panzer, pelzige Beine und Krallen, an der Spitze abgeflacht, um Nahrung zu ernten.

Fotos 1 - 2 Johnny: Bonaire Karibik

Mithraculus cinctimanus

Banded clinging crab

 Maximum size: 5 cm

Maximum depth: 0 - 6 m

Small crab with oval carapace, slightly longer than wide.

Slightly hairy, with several blunt spines.

The outer segments of the legs are also hairy.

Photo 1 Astrid: Bonaire Caribbean

Omalacantha bicornuta

Speck-claw decorator crab or spider crab

 Maximum length: 2 cm

This species attaches itself to sponges, scraps and other organisms.

Red claws, white spotted and banded.

Also known as the two-horned masked crab because it has two horn-like spines on its head.

Found in reefs.

Not shy, remains calm, relying on its camouflage.

Photo 1 Johnny: Bonaire Caribbean

Pelia mutica

Cryptic teardrop crab

 Maximum length: 2 cm

This masked crab attaches live sponges to its carapace and legs (see photo 2).

In photo 1 it is ‘naked’.

It has light blue to purple claws with dark spots.

Found in reefs where they sit very still when approached, relying entirely on their camouflage.

Photo 1 Johnny: Bonaire Caribbean

Photo 2 Astrid: Bonaire Caribbean

Schizophrys aspera

Common decorator crab, Red spider crab, Red sea toad,

Red decorator crab or Ornamental spider crab

 Maximum length: 10 cm

They have two short, forked interdigital spines and their first pair of legs has large claws.

Apart from the legs, their body is covered with sponges, algae, soft corals and other vegetation.


Photos 1 - 2 Johnny: Hurghada Egypt

Stenorhynchus seticornis

Yellowline arrow crab

 Maximum size: 6 cm

Carapace golden brown, triangular, with fine lines, long pointed rostrum, and long slender legs.

Mostly blue to purple claws.


They are found in the reef, often on wrecks.

Not shy, only retreat when harassed.

Photos 1 - 2 Johnny: Bonaire Caribbean

Photo 3 Astrid: Bonaire Caribbean

Stenorhynchus sp.

Stenorhynchus sp.nothing known yet

 Maximum length: ?

An as yet undescribed species.

Photos 1 - 2 Johnny: Bangka Island North Sulawesi

Xenocarcinus tuberculatus

Wire coral crab

 Maximum length: up to 1 cm

White with grey-green stripes.

Carapace with large spines.

Photos 1 - 2 Johnny: Lembeh Strait North - Sulawesi