Shedding light on the larval genus Eretmocaris: morphological larval features of two closely related trans-isthmian Lysmata species (Decapoda: Caridea: Hippolytidae) described on the basis of laboratory cultured material

Abstract

Complete larval series are known for only three of the 39 valid species worldwide in the genus Lysmata. The present work deals with the larval development of two closely related trans-isthmian species of Lysmata, L. galapagensis (eastern PaciWc Ocean), and L. moorei (southwestern Atlantic Ocean), using laboratory cultured material. The morphological features of the Wrst four zoeal stages of both species, the Wfth to seventh stages of L. galapagensis, and the last stage of L. moorei are described and compared with the larval descriptions currently available for the genus. Larvae of both species hatch with a similar form to L. seticaudata, with their Wrst and Wfth pereiopods as buds, and show a very steady development of their morphological characters. The zoeal characters match the phylogenetic results currently available for the genus Lysmata and L. galapagensis, L. moorei and L. seticaudata belong to the same monophyletic clade. We hypothesize that the larvae of all species within this clade will hatch with the Wrst and Wfth pereiopods as buds and will present a maximum of nine zoeal stages. The relationships between the studied material and the composite larval genus Eretmocaris are discussed, with emphasis on Eretmocaris corniger which has an extremely long rostrum and a spine on the dorsal surface of the third pleomere, characters also recorded in L. galapagensis. The larval forms earlier described as the tropical eastern PaciWc E. corniger are matched to a known Lysmata species, L. galapagensis. The identity of E. corniger larvae recorded one century ago from the tropical eastern Atlantic is also discussed.

Phylogenetics reveals the crustacean order Amphionidacea to be larval shrimps (Decapoda: Caridea)

“…In recent years, some of these forms have been linked to adult genera, either on the basis of direct rearing or molecular evidence. For instance, Eretmocaris was shown to be the zoeal stage of Lysmata based on laboratory rearing 24 , whilst COI data conclusively showed Galatheacaris to be the decapodid stage of Eugonatonotus 15 and Icotopus to be the late larvae of Plesionika 25 .…”

Unweaving hippolytoid systematics (Crustacea, Decapoda, Hippolytidae): resurrection of several families

“…Indeed, in Lysmata , the fifth pereiopod in the second zoea stage becomes extremely long (persisting throughout later stages), with the propodus widening out into a paddle shape (Gurney ; Bartilotti et al . ), which is thought to have a dual role in feeding as well as predator avoidance (Rufino & Jones ). This could potentially be a synapomorphic character, as the same development has been noted in Exhippolysmata ensirostris (Kemp, ) (see Pillai ), and no other hippolytoid species, for which larval development is known, exhibits a similar development.…”

Ontogenetic shift of spectral sensitivity in the larval phototaxis of two sympatric caridean shrimp, Lysmata wurdemanni and L. boggessi (Decapoda: Lysmatidae)

“…Molecular phylogeny of Lysmata and closely allied taxa strongly support protandric simultaneous hermaphroditism within the group Fiedler et al 2010). Newly hatched Lysmata larvae undergo multiple development stages as zoeae before metamorphosing into juveniles (Calado et al 2004;Bartilotti et al 2012). Larvae hatch at night and are immediately attracted to light.…”