Leuconidae, Sars, 1878

Brito, Ayrton Do Ramo & Serejo, Cristiana Silveira, 2023, Leuconidae Sars, 1878 (Crustacea: Cumacea) from the southwestern Atlantic, filling the distribution gap along the Brazilian coast, Zootaxa 5383 (2), pp. 101-134 : 130-131

Genera of Leuconidae

Among the Cumacea with pleotelson, Leuconidae present the truncated mandible with wide molar process, described as a diagnostic character since its original description ( Sars 1878; 1879) and still used in the present day to characterize the group in combination with other leuconid characters ( Heard et al. 2007). Within the pleotelson clade, the genus Campylaspis ( Nannastacidae ) also is characterized by a truncate mandible (but with styliform molar process), in combination with nannastacid characters ( Heard et al. 2007).

Watling (1991) proposedawide reviewof thefamilygivinggenera diagnoses, descriptionsoffivenewgeneraand division of the genus Leucon into five subgenera. Watling and Gerken (2023) have been compiling data on Cumacea systematic available in the World Register of Marine Species (WoRMS). However, there are some disagreements regarding the literature and the WoRMS database of Leuconidae genera that will be elucidated below.

The World Register of Marine Species presents 20 Leuconidae genera, however there are inconsistencies based on the literature. Within WoRMS, Epileucon Jones, 1956 appears both as a genus and subgenus of Leucon . Băcescu (1988) considered Epileucon as a subgenus of Leucon , a classification accepted by Watling’s (1991) revision. The monotypic genus Americuma it is not valid, as Americuma heardi Băcescu, 1979 was transferred to the genus Styloptocuma ( Nannastacidae ) ( Petrescu 1999). Haye’s (2004) revision of the Bodotriidae transferred Coricuma to the Bodotriidae ( Table 2 ).

Pseudeudorella was described by Mühlenhardt-Siegel (2008) based on Eudorella redacticruris Watling and McCann, 1997 , due to the absence of pereopod 5 in both sexes and the presence of penial lobes in males. Pseudeudorella is not mentioned in WoRMS, and there is no literature that considers it as a junior synonym of Eudorella . As a conclusion, we consider Pseudeudorella as a valid genus, despite Watling and McCann (1997) stating that both characters (Pereopod 5 absent and penial lobes in males) were not relevant to erect a new genus.

From this literature review and including Gyneleucon gen. nov., it is concluded that Leuconidae has 19 valid genera ( Table 2 ).