Atlas of Crustacean Larvae

34. Stomatopoda

34 general: Stomatopods (mantis shrimps) are well known as highly efficient predators. They are readily recognized by their triflagellate antennules, articulated rostrum, and subchelate maxillipeds, with the second developed as a massive raptorial claw. Almost 500 extant species are known, currently arrayed in 17 families and 7 superfamilies (F. Schram and Müller 2004; Ahyong et al. 2008, 2011). The Stomatopoda includes all extant representatives of the subclass Hoplocarida, with a fossil record that begins in the Palaeozoic (F. Schram 2007; J. Haug et al. 2010a). All known stomatopods are freeliving , although some lysiosquilloids live in mated pairs. Most species live in shallow marine or estuarine habitats, but some occur on the outer continental shelf or slope. The life cycle consists of a series of larval stages, all of which are free living, with development following one of three sequences: (1) antizoea, erichthus, post-larva, juvenile, adult (the Lysiosquilloidea); (2) pseudozoea, erichthus, post-larva, juvenile, adult (the Gonodactyloidea, Parasquilloidea, and Eurysquilloidea ); and (3) pseudozoea, alima, post-larva, juvenile, adult (the Squilloidea). larval types: Stomatopod larvae are among the most conspicuous crustacean larvae, not only because of their substantial size (up to 50 mm in length), but also because of their large functional raptorial maxilliped 2. Antizoea, Pseudozoea: Among the two major hatching types, lysiosquilloids (and probably erythrosquilloids, owing to their shared maxilliped structure) hatch at an early stage of development, called an antizoea (fig. 34.1A, B), whereas larvae of other superfamilies (where known) hatch as pseudozoeae (figs. 34.1C; 34.2J). Ericthus, Alima: Both antizoeae and pseudozoeae (except those of squilloids) develop into an erichthus (figs. 34.1F–H; 34.2B–F, K–Q). The squilloid pseudozoea (sometimes called a squillerichthus) develops into an alima (figs. 34.1D, E; 34.2G– I). The alima and erichthus proceed through post-larval and juvenile stages before becoming adults. For larval development in the superfamilies Bathysquilloidea and Erythrosquilloidea , only a single late pelagic bathysquilloid larva and erythrosquilloid post-larva have been identified (Manning 1991; Froglia 1992). Differing larval types are defined for different stomatopod lineages, but the larvae of all lineages develop through several discrete ecological and functional stages. Early-stage larvae—typically the first two or three stages, termed propelagic stages (fig. 34.2J–L)—are lecithotrophic and live in the burrow of the female parent. Subsequent stages are pelagic (fig. 34.2M–Q) and capture prey using their raptorial claws. During the pelagic stages, thoracic (pereonal) and abdominal (pleonal) appendages develop progressively. Larvae having the full complement of thoracic appendages (five pairs of maxillipeds and three pairs of pereopods) and abdominal appendages (five pairs of pleopods and one pair of uropods) are at the synzoeal stage (e.g., fig. 34.1D–H). Stomatopods typically have four to nine pelagic stages, although development in Heterosquilla tricarinata from New Zealand is abbreviated, with only one propelagic and two pelagic stages prior to the post-larva. As in natant decapods, the number of pelagic larval stages in at least some species of stomatopods is not constant, probably influenced by environmental conditions at the time of settlement (S. Morgan and Goy 1987). The molt from the last pelagic larva to the postlarva marks the transition from a planktonic to a benthic habit. Stomatopod larvae are transparent, aside from the yelloworange yolk of the propelagic stages, dark eye pigmentation at all stages, and minor pigmentation that may be present on maxillipeds 3–5 and mouthparts in the late pelagic stages. Significant body pigmentation is acquired prior to settlement at the post-larval stage. morphology Antizoeae: Antizoeae are the hatching larvae of lysiosquilloids , characterized by sessile eyes, uniflagellate antennules, five pairs of biramous thoracic appendages, the absence of Shane T. Ahyong Joachim T. Haug Carolin Haug Shane T. Ahyong, Joachim T. Haug, and Carolin Haug Stomatopoda 186 Shane T. Ahyong, Joachim T. Haug, and Carolin Haug abdominal appendages, and minimal segmentation. The carapace has a fixed spiniform rostrum, and slender posterolateral and posterodorsal spines; it is greatly enlarged and dorsally covers most of the abdomen, except for the posterior two or three somites and telson. Pseudozoeae: Pseudozoeae are the hatching larvae of squilloids, gonodactyloids, parasquilloids, and probably eurysquilloids . Features include pedunculate eyes, biflagellate antennules , two pairs of uniramous thoracic appendages (maxillipeds 1 and 2), and four (squilloids) or five (other groups) pairs of natatory biramous pleopods. The carapace of pseudozoeae has similar spination to that in the antizoeae, but the former covers only the anterior thoracic somites, perhaps reflecting their later stage of development at hatching...