Hemisquillidae Family of Mantis Shrimp

Peacock Mantis Shrimp, Hemisquilla californiensis. A representative of the Hemisquillidae Family of Mantis Shrimp.

Phylogeny:  Hemisquillidae Mantis Shrimp and members of the Hemisquillidae Family in the Phylum Arthropoda. They are in the Class Malacostraca and the Order Stomatopod. They are named for the resemblance of their “arms” and stalked eyes of Praying Mantis insects. There are approximately four hundred and eighty species of Mantis Shrimp, that have been placed in seventeen families of which members of eight are found along the Pacific Coast of Mexico. The Mantis Shrimp Stomatopods are separated into two categories based on the second pair of thoracic appendages – Spearers and Smashers. Spearers have barbed appendages that they use to spear soft prey such as fish. Smashers have a thickened portion at the “elbow” of the appendage and they strike hard shelled prey with a force equal to that of a small caliber bullet. Hemisquillidae Mantis Shrimp are smashers. There are four species in the Hemisquillidae Family with only this species being found along the Pacific Coast of Mexico.

Distribution:  Stomatopods are found worldwide, in tropical to sub-Antarctic waters with most found on tropical coral reefs and within soft substrates in shallow water, though some are found at depths exceeding 1,500 m (4,920 feet). Some species can form pelagic swarms. They reside in “U”-shaped burrows in soft-substrate, or under rocks on soft substrate. Most live in shallow, temperate waters, but some are found as deep as 200 m (650 feet).

Morphology:  Hemisquillid Mantis Shrimp have 5 head segments, 8 thoracic segments, and 6 abdominal segments. The head and thorax are usually combined as a cephalothorax. The head includes a pair of antennae, a pair of antennules, and mouth parts. These animals have stomachs with 2 chambers. The next four pairs of thoracic appendages are subchelate (pincer-like) and are used for handling food and for burrowing. The last three pairs are used for walking. The uropods and telson comprise the tail fan.  Some have the ability to generate a fluorescent display that is used to signal others of their kind, and, perhaps, other species. They have eyes that are among the most complex in the animal kingdom that can see the full range of visible light colors, as well as ultraviolet and polarized light. The Stomatopods have 15 classes of photoreceptors; humans have four classes. They range in size from 1 cm (0.4 inches) to 48 cm (18 inches).

Ecosystems Role:  They may be nocturnal or diurnal and feed on cnidarians, crustaceans, fish, and mollusks. The force of their attacks break the shells and usually kills their prey instantly. The speed at which stomatopods move this second appendage is among the fastest movement of any animal, often completing the action in five to eight milliseconds. In turn they are preyed upon by by fish and octopus.

Reproduction:  Some species of Mantis Shrimps are monogamous, sharing the same burrow with their partner for more than twenty years.