Stenorhynchus seticornis, or the yellowline arrow crab, is a crustacean with a triangular body, a long, pointed rostrum (snout), and long, spindly legs. Its color is variable, often golden-brown or yellow, with lines on the carapace and reddish or yellow legs. The claws are frequently blue or violet-tipped.
Physical characteristics
Body: Triangular shape, resembling an arrowhead.
Rostrum: An extremely elongated, pointed snout, often with serrated edges.
Legs: Long and thin, sometimes spanning up to 10 cm (3.9 in).
Claws: The first pair of legs are transformed into claws, which are often blue or violet at the tips.
Size: Carapace length is typically 3 to 6 cm (1.2 to 2.4 in).
Coloration
Body: Can be golden, yellow, or cream.
Markings: Often features fine dark, brown, or iridescent blue lines on the carapace.
Legs: Can be reddish or yellow.
Habitat and behavior
Habitat: Found in the western Atlantic, from North Carolina to Brazil, and is common on coral reefs in the Caribbean.
Behavior: It is a nocturnal scavenger that feeds on small invertebrates, detritus, and parasites off of fish.
Association: Often lives in groups near sea anemones.
Percnon gibbesi, commonly known as the Sally Lightfoot Crab or Nimble Spray Crab, is a marine crab species characterized by its very flat, thin, and wide carapace (shell). It has a distinctive red to brown coloration, sometimes with fine green marbling, and legs with yellow rings at the joints. Adults can reach a carapace width of about 30 millimeters (1.2 inches). They are known for their agility and speed, especially in their natural rocky habitat.
Physical Characteristics:
Carapace: Flat and thin, with a width of about 30mm.
Coloration: Varies from red to brown, sometimes with green marbling.
Legs: Long and flattened, with yellow rings at the joints.
Spines: Each of the five pairs of walking legs has a row of spines along the leading edge.
Habitat and Behavior:
Percnon gibbesi is native to the Eastern Atlantic, the Mediterranean, and the Canary Islands.
It is considered an invasive species in many parts of the Mediterranean.
It is commonly found in rocky, intertidal and subtidal zones, often hiding under rocks and in crevices.
They are known for their scavenging behavior, feeding on algae, detritus, and small invertebrates.
While generally reef-safe, larger individuals can become aggressive and may prey on small fish and other invertebrates
The Ciliopagurus strigatus, commonly known as the Halloween hermit crab, is a brightly colored hermit crab with a vibrant orange and black striped appearance. They are popular in marine aquariums due to their distinctive colors and usefulness as algae eaters and scavengers.
Key features and characteristics:
Appearance:
The Halloween hermit crab is easily recognizable by its bright orange and red striped "stockings". They also have a small claw on the left side.
Habitat:
They are found in the Central Pacific region, and are often associated with reef environments.
Diet:
They are omnivores, feeding on algae, detritus, leftover food, and sometimes other small creatures.
Behavior:
They are scavengers, sifting through the substrate to clean up detritus and algae. They also help aerate the substrate by moving the sand.
Reef-safe:
Generally considered reef-safe, they do not pose a threat to reef corals or other reef inhabitants.
Shells:
They live in borrowed shells, usually abandoned snail shells, and may even attack and consume snails to obtain a shell.
Maintenance:
In aquariums, they should be provided with a variety of shells to choose from, and their diet may need to be supplemented with algae and other food items if necessary.
In short, the Halloween hermit crab is a visually appealing and useful addition to a marine aquarium, known for its vibrant colors, algae-eating habits, and cleaning skills
