Macropodia tenuirostris

Adult M. tenuirostris reach a carapace breadth of 11 millimeters, and a carapace length of 16[2] to 32 millimeters. The carapace is chestnut in color and triangular in shape. Its surface is smooth to slightly coarse. The frontal region − its rostrum − is thick, long, very narrow, slightly bent upwards, and contains numerous hook-setae. From a dorsal view, the eyestalks are clearly visible. Aside from the chelipeds, large in males and slender in females, the limbs are long and thin, with the dactylus of the fourth and fifth legs fairly bent.[3]

The slender spider crab is a free living, solitary, epibenthic, and gonochoristic omnivore. It has a life span of 3 to 5 years, with the duration of the larval development of 11 to 30 days.[2] It can be found in European waters, from the Faroe Islands to Portugal, most commonly around the British Isles.[1][2] It usually occurs in waters 9–97 meters deep, on muddy to hard substrata, or in estuaries. However, it can occasionally be found at depths down to 300 meters, on Sertularella colonies.[2][3]