The speckled swimming crab (Arenaeus cribrarius, 71 island records, the fourth most-recorded crustacean here) is the surf-zone crab of the Gulf beach: light brown to olive with dense pale round spots, nine teeth along each side of the shell, paddle-shaped hind legs, and up to about five or six inches across . It buries itself completely with a gap left open so water reaches the gills, and NPS describes it as an aggressive ambush hunter of coquinas and mole crabs that favors heavy surf and slightly hypersaline water at Padre Island National Seashore . It is one of the animals a wader's foot finds first.
The calico box crab or Dolly Varden crab (Hepatus epheliticus, 6 island records) is a rounder, three-inch crab patterned with red patches ringed in darker color; it lies buried with only the eyes out, often carries a hitchhiker anemone on its back, and — the detail that matters on this island — NPS calls it a major part of the Kemp's ridley sea turtle's diet (chapter 02). The speckled purse crab (Persephona aquilonaris, 4) and the blotched swimming crab (Achelous spinimanus, 2 county) round out the list . The sargassum swimming crab (Portunus sayi) is treated under the sargassum community below.
Observe responsibly
Wildlife, tides and access conditions change. Keep a respectful distance, do not feed wildlife, stay out of dunes and marked nesting areas, and use current official rules before fishing or handling any catch.