Figure 1. Some morphological characters of shrimps from the genera Rhynchocinetes and Cinetorhynchus. A, 'cage' position during mating in the shrimp Rhynchocinetes typus, the only species of marine caridean shrimp for which alternative mating tactics have been demonstrated so far. Notice the well-developed third maxillipeds and chelipeds characteristic of the 'robustus' male morphotype. B, habitus (view of the entire animal) of the hinged-beak shrimp genus Cinetorhynchus. C, lateral view of the rostrum of R. typus. Notice the articulation (arrow) of the rostrum with the remainder of the carapace. D, lateral view of the rostrum of Cinetorhynchus rigens. Notice the indistinct articulation between the carapace and the rostrum (compared with Rhynchocinetes). E, dorsal view of the carapace in C. rigens. Notice the three teeth at the median carina of the carapace and the absence of a supraorbital spine. F, dorsal view of the carapace in R. typus. Notice the two acute teeth at the median carina of the carapace and the supraorbital spine. G, lateral view of the fourth and fifth pereopods of R. typus. Notice the presence of only one row of meral spines on these pereopods. H, lateral view of the fourth and fifth pereopods of C. rigens. Notice the presence of two rows of meral spines. A from Correa et al. (2003); B–H from de Melo (2007).

Published as part of Baeza, J. Antonio, Bauer, Raymond T., Okuno, Junji & Thiel, Martin, 2014, Molecular phylogeny of hinge-beak shrimps (Decapoda: Caridea: Rhynchocinetes and Cinetorhynchus) and allies: a formal test of familiar and generic monophyly using a multilocus phylogeny, pp. 426-450 in Zoological Journal of the Linnean Society 172 (2) on page 428, DOI: 10.1111/zoj.12173, http://zenodo.org/record/5314330