Leuconidae Sars, 1878 (Crustacea: Cumacea) from the southwestern Atlantic, filling the distribution gap along the Brazilian coast Author Brito, Ayrton Do Ramo Setor de Carcinologia, Museu Nacional / Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão s / n, 20940 - 040, Rio de Janeiro, Brazil & Programa de Pós-graduação em Ciências Biológicas (Zoologia), Museu Nacional / Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão s / n, 20940 - 040, Rio de Janeiro, Brazil Author Serejo, Cristiana Silveira Setor de Carcinologia, Museu Nacional / Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão s / n, 20940 - 040, Rio de Janeiro, Brazil & Programa de Pós-graduação em Ciências Biológicas (Zoologia), Museu Nacional / Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão s / n, 20940 - 040, Rio de Janeiro, Brazil text Zootaxa 2023 2023-12-11 5383 2 101 134 https://www.mapress.com/zt/article/download/zootaxa.5383.2.1/52444 journal article 10.11646/zootaxa.5383.2.1 1175-5326 10350586 996315A6-A209-4DF7-B59C-0B7662741F37 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) proposed a wide review of the family giving genera diagnoses, descriptions of five new genera and 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 ). TABLE 2. Genera of Leuconidae after literature revision and compared to the World Register of Marine Species (WoRMS). The genera in bold are revised in the present study.
Genera WoRMS Present study
1 Abyssoleucon Lavrenteva & Mühlenhardt-Siegel, 2015 Valid Valid
2 Afroleucon Mühlenhardt-Siegel, 2011 Valid Valid
3 Alloeoleucon Watling & McCann, 1996 Valid Valid
Americuma Watling, 1991 Valid Nomen nudum
4 Austroleucon Watling, 1991 Valid Valid
5 Bytholeucon Watling, 1991 Valid Valid
Coricuma Watling & Breedy, 1989 Valid Bodotriidae
Epileucon Jones 1956 Valid Subgenus Leucon
6 Eudorella Norman, 1867 Valid Valid
7 Eudorellopsis Sars, 1882 Valid Valid
8 Gyneleucon gen. nov. - New genus
9 Hemileucon Calman, 1907 Valid Valid
10 Heteroleucon Calman, 1907 Valid Valid
11 Ithyleucon Corbera, 2012 Valid Valid
12 Kontiloleucon Gerken, 2016 Valid Valid
13 Leucon Krøyer, 1946 Valid Valid
14 Nippoleucon Watling, 1991 Valid Valid
15 Ommatoleucon Watling, 1991 Valid Valid
...Continued on the next page TABLE 2. (Continued)
Genera WoRMS Present study
16 Paraleucon Calman, 1907 Valid Valid
17 Phalloleucon Mühlenhardt-Siegel, 2008 Valid Valid
18 Pseudeudorella Mühlenhardt-Siegel, 2008 Not compiled Valid
19 Pseudoleucon Zimmer, 1903 Valid Valid
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 ).