Barybrotes Schioedte and Meinert, 1879

Vigneshwaran, P., Ravichandrana, S. & Kumar Ajith ,, T. T., 2022, Redescription of the monotypic micro-predatory isopod genera Alitropus H. Milne Edwards, 1840 and Barybrotes Schioedte & Meinert, 1879 (Isopoda, Cymothoida), with a taxonomic key to the Cymothooidea Leach, 1814 from India, Journal of Natural History 55 (45 - 46), pp. 2909-2934 : 2923-2924

Genus Barybrotes Schioedte and Meinert, 1879

Barybrotes Schioedte and Meinert, 1879: 280 . — Hansen, 1890: 402. — Richardson, 1910: 8. — Thielemann, 1910: 94. — Nierstrasz, 1931: 177. — Barnard, 1936: 154. — Pillai, 1954: 8. — Pillai 1967: 278. — Brandt and Poore, 2003: 898. — Kensley, 2001.

Type species. Barybrotes indus Schioedte and Meinert, 1879 by monotypy. Types held in the Zoological Museum, Natural History Museum of Denmark, University of Copenhagen.

Diagnosis. Bruce (2009) provided a provisional diagnosis for the family Barybrotidae ; the genus diagnosis is as for the family.

Remarks. The family Barybrotidae is monotypic with a single genus and species, Barybrotes Schioedte and Meinert, 1879 . Barybrotes can be identified by the elongate body; large eyes; antero-median rostrum which separates the bases of the antennae, not concealing them; the morphology of the mouthparts and the long natatory setae on the pereopods; maxilla is a minute single lobe lacking robust setae, maxilliped with only four palp articles, with article 2 elongate; and the mandible incisor retains the cirolanid form, being wide and tridentate, though somewhat narrower; pereopods 1–3 forming a strong hook, and all seven pairs by dilatation of the joints or garniture of setae are auxiliary to swimming. This genus was first included under the family Corallanidae by Schioedte and Meinert (1879). Two species, Baryhrotes indus and Baryhrotes agilis , were instituted by the authors of the genus. Hansen (1890) created a new family Barybrotidae for this genus and found that these species are one and the same; he adopted the name agilis as the most significant, but indus has precedence in the original authority. Similarly, according to Stebbing (1893), they are synonymous and the name indus has precedence. Schioedte and Meinert state that the male has a styliform appendage on the inner side of the inner branch of the second, third and fourth pleopods, which would be a truly remarkable feature. But Hansen (1890), who has examined the type specimens, declared that neither here nor in any other isopod does such an appendage occur on the third and fourth pleopods; it is limited, here as elsewhere, to the second. A notable feature in the species is that the seventh segment of the pereion is almost entirely concealed.

Bruce (2009) stated that the numerous characters strongly suggest the genus Barybrotes evolved from a Natatolana- like cirolanid ancestor. Differences in the morphology of the antennule peduncle, frontal lamina and pleopod setation prevent its inclusion in Natatolana , and there are several characters, normally regarded as invariable, in which Barybrotes differs from Natatolana . These variations are noted in the diagnostic and additional characters presented above and include the relative lengths of the peduncular articles of the antennule and the setation of the endopod of the pleopods.