Yellowline Arrow Crab care guide
Yellowline Arrow Crab (Stenorhynchus seticornis) — minimum tank 100 L, temperature 24-26 °C, pH 8.1-8.4.
Compiled by Aquairi from published sources · Published · Updated
Overview
Yellowline Arrow Crab (Stenorhynchus seticornis) is a marine arrow crab of the family Inachidae, listed in the Aquairi knowledge base as an intermediate-level species. Distinctive long-legged spindly spider-crab with arrow-shaped body and brown/yellow striping. Hunts bristleworms but may also pick at small inverts and slow fish.
Taxonomy
- Family: Inachidae
- Genus: Stenorhynchus
- Scientific name: Stenorhynchus seticornis
- Common synonyms: Arrow Crab, Spider Crab
Habitat
Stenorhynchus arrow crabs (family Inachidae) are spider-like majoid crabs of the western Atlantic with a long triangular body and slender legs that span far wider than the carapace. They forage at night over rockwork and the substrate. In the Aquairi knowledge base this species is recorded from Caribbean, Western Atlantic.
Tank requirements
- Minimum tank volume: 100 L (26.4 US gal)
- Adult size: 6-12 cm
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- GH: 8-12 °dGH
- KH: 8-12 °dKH
- Salinity (specific gravity): 1.024-1.026
- Lifespan: 2-5 years
Diet
The species is a carnivore, taking a wide range of foods including meaty frozen foods, sinking pellets and detritus gathered from the rockwork.
Compatibility
The Aquairi knowledge base lists this species as semi-aggressive. Suitable tank mates include Larger fish, Hardy corals. It should be kept away from Small slow fish, Feather Dusters, Small shrimp. This species is not fully reef-safe and may pick at corals, sessile invertebrates or small tank mates.
Breeding
Breeding requires an extended planktonic larval stage in open water before the young settle, which makes captive reproduction very difficult and rarely accomplished in home aquaria. Most specimens in the hobby are wild-collected.
Breeding the Yellowline Arrow Crab (Stenorhynchus seticornis)
Overview
Stenorhynchus seticornis is a long-legged spider crab of the family Inachidae from the western Atlantic, ranging from North Carolina and Bermuda through the Caribbean to Brazil on coral reefs at depths of about 3–9 m. The carapace reaches up to 6 cm with legs spanning around 10 cm. It is nocturnal, territorial and shows negative phototaxis, feeding on small feather duster worms and other reef invertebrates.
Sexing
As in other crabs, the sexes are distinguished by abdominal shape, and a gravid female is identified by the egg mass carried on her pleopods. Mating involves the male transferring a spermatophore to the female, after which she fertilizes and broods the eggs.
Conditioning
A varied carnivorous diet of small reef invertebrates maintains adults in condition, and the species is territorial, so housing more than one requires space. No documented protocol reliably induces or completes reproduction in a home reef, because the larvae are planktonic and cannot be reared in a display.
Breeding Setup
No practical home breeding setup exists. After spermatophore transfer the female carries fertilized eggs on her pleopods until they hatch into zoea larvae, which then enter the plankton and require open-water rearing conditions unavailable in a closed system.
Spawning & Larvae
Fertilized eggs are carried on the female's pleopods until ready to hatch into zoea larvae. The larvae swim toward the ocean surface and feed on plankton, developing through several molts before metamorphosing into the adult form. This extended planktonic phase is the central obstacle to captive rearing.
Common Challenges
- Surface-seeking planktonic zoea are removed by filtration and skimming.
- Larvae require continuous planktonic food over multiple molts.
- Territorial adults are aggressive toward conspecifics.
- Adults may prey on small tankmates, complicating cohabitation.