How related are they?
Same family, Mithracidae (Mithracid spider crabs): close cousins
They split at the genus level: the Spider Crab belongs to Mithraculus (Clinging crabs), the Pitho Crab to Pitho.
Find the Spider Crab on the tree · Find the Pitho Crab on the tree
Family lines, side by side
Highlighted rows are groups both animals belong to. The marked row is where their lines go separate ways.
| Rank | Spider Crab | Pitho Crab |
|---|---|---|
| Kingdom | Animalia Animals | |
| Phylum | Arthropoda Arthropods | |
| Subphylum | Crustacea Crustaceans | |
| Superclass | Multicrustacea | |
| Class | Malacostraca Malacostracans | |
| Subclass | Eumalacostraca | |
| Superorder | Eucarida | |
| Order | Decapoda Decapods | |
| Suborder | Pleocyemata Egg-carrying decapods | |
| Infraorder | Brachyura true crabs | |
| Section | Eubrachyura | |
| Subsection | Heterotremata | |
| Superfamily | Majoidea spider crabs | |
| Family | Mithracidae Mithracid spider crabs | |
| Genus split | Mithraculus Clinging crabs | Pitho |
| Species | Mithraculus forceps Red-ridged Clinging Crab | Pitho mirabilis Pitho Crab |
Care, side by side
| Fact | Spider Crab | Pitho Crab |
|---|---|---|
| Type | Invertebrate · Crab | Invertebrate · Crab |
| Care level | Easy | Easy |
| Reef safe | With caution | Yes |
| Temperament | Peaceful | Peaceful |
| Diet | Omnivore | Omnivore |
| Favorite foods | Hair and film algae, Bubble algae, Macroalgae | Hair and turf algae, Bubble algae (Valonia), Caulerpa and Dictyota |
| Max size | 1 in (2.5 cm) | 1.5 in (3.8 cm) |
| Minimum tank | 26 gal | 20 gal |
| Temperature | 72–82 °F | 72–78 °F |
| Salinity (SG) | — | 1.023–1.025 |
| pH | 8–8.3 | 8.1–8.4 |
| Lifespan | No published data. | About 1-3 or more years with proper care, per one retailer (Top Shelf Aquatics); no published data. |
| Breeding | Hard | Not achieved |
| Conservation (IUCN) | Not Evaluated | Not Evaluated |