An Update on Reproduction in Ghost Shrimps (Decapoda: Axiidea) and Mud Lobsters (Decapoda: Gebiidea)

Abstract

In this report, I review the taxonomic history, body adaptations, ecology, and reproduction of the infraorders Axiidea (ghost shrimps) and Gebiidea (mud lobsters). Known until recently as the "Thalassinidea," modern classification divided Axiidea into six families and Gebiidea into five. Ghost shrimps are characterized by having the first and second pereiopod chelate and a soft and delicate body, whereas mud lobsters possess the first pereiopod chelate or subchelate and second pereiopod subchelate or simple with a hard and heavily calcified body. Among the main body adaptations of these organisms are distinguished: (i) carapace laterally compressed, (ii) pleon longer than the cephalothorax in ghost shrimps but usually shorter in mud lobsters, and (iii) anterior feet thrown directly forward. Current accounting of axiideans and gebiideans reaches around 781 and 240 extant species, respectively, with major number of species in Callianassidae and Upogebiidae within of each clade. Male reproductive system involves paired testes linked to the vas deferens that open in gonopores on the ventral coxal segment of the fifth pereiopod. In females, the reproductive system is composed of paired and colored ovaries, one ovary shorter than another, and a pair of short and translucent oviducts linking each ovary to the gonopore, this latter located on the ventral coxal of the third pereiopod. When present in males, the first pleopod is sexually dimorphic. Most ghost shrimps show distinct sexual dimorphism in body size and the major cheliped which become them in a promising group for growth studies. Hypertrophied chelipeds in males are often used to defend galleries against invasion from other shrimps from the same or opposite sex or during the intense male-to-male competition for sexual partners. Knowledge about sexual systems of these species remains limited; however, available information suggests that hermaphroditism might be commonly present in axiideans and gebiideans. Regarding mating systems, all species of ghost shrimp and mud lobster with solitary habits and remarkable sexual dimorphism in the major cheliped are expected to be polygamous. Finally, considerable variability among Axiidea and Gebiidea species in fecundity and egg size may indicate important differences in the reproductive strategy and may also reflect a latitudinal trend as observed in other decapods.

Distribution and Sediment Selection by the Mud Shrimp Upogebia noronhensis (Crustacea: Thalassinidea) and the Potential Effects on the Associated Macroinfaunal Community

“…Sediment reworking rates found for U. pugettensis suggests that U. noronhensis may generate high bioturbation due to their whole-year mating behavior, as males become more active in building new galleries when searching for a partner [24,26,51]. Therefore, U. noronhensis burrowing activities may still be sufficient to affect the surrounding fauna in zones of high abundances such as those observed in this study (ca.…”

The Axiidea in the Museum of Oceanography Petrônio Alves Coelho, Recife, Brazil, with Some Remarks on the Biology of the Species

“…The infraorder Axiidea de Saint Laurent, 1979 [1] encompasses the so-called ghost shrimps, mud lobsters or burrowing shrimps [2][3][4]. This infraorder represents one clade of marine decapods with a body form completely adapted for a fossorial lifestyle who are an important benthic component of sandy or muddy intertidal, shallow subtidal and deep-sea habitats worldwide [3,5,6].…”

Departing from an ideal: An asymmetric, bimodal and non‐Equatorial latitudinal gradient of marine diversity in Western Atlantic burrowing shrimps (Decapoda: Axiidea and Gebiidea)

“…Given its prominent north–south orientation, and continuous extension crossing both hemispheres, the WA coast represents an excellent study system to evaluate patterns and processes related to the LDG. We used burrowing shrimps as study model, a diverse group that represents two clades of marine decapods with a body form completely adapted for a fossorial lifestyle and that are an important benthic component of sandy or muddy intertidal and shallow subtidal habitats worldwide (Hernáez, 2018a). These organisms are known for constructing burrows of different shapes and depths (Griffis & Suchanek, 1991) and for playing an important role in shaping the community structure (Pillay, 2019).…”