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 Eudorella helenae sp. nov. ( Fig. 1D , 11 , 12 and 13 ) Material examined. Holotype female, 2.8 mm , #SANSED6 A03- R2 (500), MNRJ 30572 . Paratypes : female, 3.1 mm , HAB11 A3, MNRJ 28957 (dissected, lost in the fire) ; female, 2.6 mm , #SANSED5 G03- R2 (500) , MNRJ 30571 (dissected) ; 2 females , 2.4 mm , #SANSED6 A03- R2 (500) , MNRJ 30573 ; female, 2.4 mm , #SANSED6 A03- R3 (500) , MNRJ 30574 ; 11 females , 1.2–2.4 mm , male, 2.0 mm, #SANSED6 A03- R3 (300) , MNRJ 30575 ; female, 2.5 mm , #SANSED6 C03- R2 (500) , MNRJ 30576 ; male, 2.4 mm , #SANSED5 G03- R3 (500) , MNRJ 30577 ; male, 2.4 mm , #SANSED5 H03- R2 (500) , MNRJ 30578 ; male, 2.4 mm , #SANSED5 H03- R3 (500) , MNRJ 30579 ; male, 2.1 mm , 3 females , 1.6–1.8 mm , #SANSED5 H03- R3 (300) , MNRJ 30580 ; 3 females , 2.1– 1.5 mm , #SANSED9 A03- R1 (300) , MNRJ 30581 ; female, 2.7 mm , #SANSED9 B03- R2 (500) , MNRJ 30582 ; female, 2.4 mm , #SANSED9 B03- R3 (300) , MNRJ 30583 ; female, 2.6 mm , #SANSED9 B04- R3 (500) , MNRJ 30570 ; female, 1.8 mm , #SANSED9 E02- R1 (300) , MNRJ 30584 ; female, 2.0 mm, #SANSED9 E02- R2 (500) , MNRJ 30585 ; female, 1.5 mm , #SANSED9 E02- R3 (300) , MNRJ 30586 ; female, 2.8 mm , #SANSED9 F03- R3 (500) , MNRJ 30587 ; 2 females , 2.7 mm , #SANSED9 G03- R1 (500) , MNRJ 30588 ; male, 1.7 mm , female 1.1 mm , #SANSED9 G03- R3 (300) , MNRJ 30589 ; female, 2.8 mm , #SANSED9 G04- R3 (500) , MNRJ 30590 ; male, 2.4 mm , female 2.4 mm , #SANSED9 H03- R1 (500) , MNRJ 30591 ; female, 1.5 mm , SANSED9 H03- R1 (300) , MNRJ 30592 ; 2 female , 1.8 and 1.9 mm , #SANSED9 H03- R2 (500) , MNRJ 30593 ; male, 2.3 mm , #SANSED9 H03- R2 (300) , MNRJ 30594 . Additional material (lost in the fire): male, 2.5 mm , #HAB11 A3, MNRJ 28958 ; 3 females , 2–2.5 mm . #HAB7 A6, MNRJ 28953 ; female, 2 mm , #HAB11 A1, MNRJ 28954 ; 12 females , 1.8–3 mm , 3 males , 2.1–2.4 mm . #HAB11 A2, MNRJ 28955 ; 19 females , 1.6–3.1 mm , 14 males , 1.9–2.5 mm , #HAB11 A3, MNRJ 28956 ; 31 females , 1.7–3.3 mm , 5 males , 2.1–2.3 mm , #HAB13 A3, MNRJ 28959 ; female, 2.5 mm , #HAB13 H5, MNRJ 28960 ; female, not measured, #HAB17 A2, MNRJ 28961 ; 14 females , 1.5–2.5 mm , male, not measured, #HAB17 A3, MNRJ 28962 ; female, 3.5 mm , male, 2.1 mm , #HAB17 A4, MNRJ 28963 ; female, 1.3 mm , # AMB3 E5, MNRJ 28952 . Development. Females: mature longer than 2.4 mm , preparatory between 2.1–2.4, immature between 1.5 and 2.1 mm , manca 2 shorter than 1.5 mm . Male: mature unknown, preparatory longer than 2.5 mm , second immature between 2.0 and 2.4 mm , first immature shorter than 1.8 mm . Type locality. Santos Basin, PR , Brazil , 26°09’25”S – 47°13’00”W ; 100 m . Distribution. Brazil : Santos Basin (RJ, SP, PR , SC), Campos Basin (RJ), Espírito Santo Basin (ES); 25– 392 m . Etymology. the name “ helenae ” is in honor of Dr. Helena Lavrado (IB/UFRJ) coordinator of the PCR-BS project, and one of the professors of the first author during his master’s degree. Diagnosis. Body covered with many setae. Pseudorostrum lobes with numerous long simple setae. Small peak between pseudorostrum and frontal lobe. Carapace ventral corner rounded and with serration. Pereopod 2 merus as long as carpus and dactylus with 12 long simple setae. Uropodal exopod slightly longer than endopodal article 1, endopodal article 2 with terminal setae fused. Description: Holotype , mature female, MNRJ 30572. FIGURE 11. Eudorella helenae sp. nov. Holotype: habitus without appendages and carapace with zoom; mature female, 2.8 mm, #SANSED6 A03-R2 (500), MNRJ 30572. Mature female, 2.8 mm . Carapace 0.7 times pereon length including pseudorostrum frontal margin, with many setae on integument, longer and tiny lateral setae behind frontal lobe, unarmed dorsally; pseudorostrum totally dorsal, with brush of dorsal setae, tip extending slightly higher than frontal lobe making a peak; antennal notch as large sinus with row of 3 teeth above; anteroventral corner rounded with serration. Pleon 0.6 times total body length with many scattered setae ( Figs. 1 D and 11 ). Paratype . Mature female, 3.1 mm , MNRJ 28904 (lost in the fire) . Antenna 1, geniculate between articles 2 and 3; article 1, 0.6 times article 2 length, with plumose setae; article 2, 1.6 times longer than 3 with plumose setae; article 3 with plumose setae; main flagellum of 3 articles, article 1 with 3 plumose setae on inner margin and distal simple seta, article 2 with 2 distal simple setae, article 3 with simple setae and 2 aesthetascs; accessory flagellum of 1 article, slightly shorter than main flagellum article 1 ( Fig. 12 a 1 ). Antenna 2 rudimentary ( Fig. 12 a 2 ). Mandibles, basis truncate, incisor with 2 distal simple setae, lacinia mobilis with 4 cusps ( Fig. 12 md). Maxilla 1 with 2 endites, palp with one bristle (broken during dissection) ( Fig. 12 mx1). Maxilla 2 with 3 endites; broad endite with row of distal plumose setae; narrow endites with simple setae ( Fig. 12 mx2). Maxilliped 1, basis with long plumose seta; ischium absent; carpus and propodus with plumose setae at outer distal corner and numerous plumose setae on inner margin; dactylus with strong terminal and 2 subterminal plumose setae ( Fig. 12 mxlp 1). Maxilliped 2, basis about 0.4 times length of remaining articles together, with plumose seta at distal inner corner; merus with plumose setae on distal inner margin; carpus with 4–5 plumose setae along inner margin; propodus with long plumose seta on outer margin and about 7 plumose setae on inner margin; dactylus with strong terminal setae and 2 subterminal simple setae ( Fig. 12 mxlp 2). Maxilliped 3, basis 0.9 times length of remaining articles together, with plumose setae on inner margin, distolateral corner with 3 long plumose setae; ischium with plumose setae on inner margin; merus with long plumose seta at distal outer corner and plumose setae on inner margin; carpus with plumose setae on inner margin and long simple seta at outer corner; dactylus with strong terminal seta and 2 subterminal simple setae; exopod flagellum with 3 articles ( Fig. 12 mxlp3). FIGURE 12. Eudorella helenae sp. nov. Paratype (Lost in the fire): carapace female, antenna 1–2, mandible, maxilla 1–2 and maxillipeds; mature female, 3.1 mm, #HAB11 A3, MNRJ 28957. Additional material (lost in the fire): Carapace preparatory male: 2.5 mm, #HAB11 A3, MNRJ 28958. FIGURE 13. Eudorella helenae sp. nov. Paratype (lost in the fire): mature female, 3.1 mm, HAB11 A3, MNRJ 28957. Habitus, pereopods and uropod (peduncle of uropod, dorsodistal seta broken, dashed line). Pereopod 1, basis 0.3 times length of remaining articles together with plumose setae; ischium naked; merus, carpus and propodus with tiny plumose setae; dactylus with strong terminal simple setae a 3 pair of subterminal simple setae. exopod flagellum with 4 articles ( Fig. 12 p 1 ). Pereopod 2, basis 0.7 times length of remaining articles together with simple and plumose setae; ischium absent; merus with tiny plumose setae; carpus with cuspidate setae at outer corner; propodus naked; dactylus with 12 long simple setae ( Fig. 13 p 2 ). Pereopod 3, basis 1.25 times length of remaining articles together with plumose setae; ischium with simple seta; merus with long plumose setae; carpus with plumose setae; propodus with annulate seta; dactylus small with long simple setae ( Fig. 13 p 3 ). Pereopod 4, basis 1.6 times length of remaining articles together with plumose setae; ischium naked; merus with 2 long plumose seta; carpus with plumose setae; propodus with simple and annulate setae; dactylus small with long simple seta ( Fig. 13 p 4 ). Pereopod 5, basis 1.4 times length of remaining articles together with plumose setae; ischium, merus with plumose setae; carpus with plumose setae; propodus with annulate seta; dactylus small with long simple seta ( Fig. 13 p 5 ). Uropod peduncle longer than pleonite 6 with 4–6 cuspidate setae on inner margin, dorsodistal seta longer than half peduncle (but often broken); endopod 2-articulate, article 1, 3.5 times article 2 length (excluding terminal seta), with 6 cuspidate setae on inner margin, article 2 with 2 cuspidate setae on inner margin, terminal setae fused to article; exopod slightly longer than endopodal article 1 with 5 plumose setae on inner margin and 3 terminal plumose setae ( Fig. 13 u ). Variations: Tooth under antennal notch variates in size on mature females ( Fig. 12 c-female and 13). Preparatory male, carapace without antennal notch, 3 teeth on frontal margin, anteroventral corner rounded with 3 teeth ( Fig. 12 c-male). Youngest stages may be more setose along the body. Outer subterminal setae of uropodal endopod may be longer or shorter than terminal setae. Remarks: Eudorella helenae sp. nov. belongs to a Eudorella group with uropodal endopod terminal setae fused to article. Among this group, E. hispida Sars, 1871 is the most similar to Eudorella helenae sp. nov. in presenting many setae along the body, pseudorostral lobes with numerous long setae, uropodal exopod slightly longer than endopodal article 1 ( Watling 1991 ). However, E. helenae sp. nov. differs from E. hispida in tip of the pseudorostrum extending slightly higher than frontal lobe making a peak ( versus not extending, peak absent), anteroventral corner rounded with small serration and one tooth under antennal notch ( versus anteroventral corner with large acute tooth, 2 teeth under antennal notch); pereopod 2 merus as long as carpus ( versus pereopod 2 carpus 1.5 times longer than merus) ( Sars 1871 ; Hansen 1920 ; Watling 1991 ).