Ephmeroporus quasimodo, Elmoor-Loureiro, Lourdes M. A., 2014

Elmoor-Loureiro, Lourdes M. A., 2014, Ephemeroporus quasimodo sp. nov. (Crustacea: Cladocera: Chydoridae), a new species from the Brazilian Cerrado, Zootaxa 3821 (1), pp. 88-100 : 89-97

publication ID	https://doi.org/ 10.11646/zootaxa.3821.1.6
publication LSID	lsid:zoobank.org:pub:302FBD81-DE1D-4CD2-9BA5-22A0CB854032
DOI	https://doi.org/10.5281/zenodo.6141894
persistent identifier	https://treatment.plazi.org/id/03CA87C4-D513-FFF8-FF5E-FA0656D0FD9B
treatment provided by	Plazi
scientific name	Ephmeroporus quasimodo
status	sp. nov.

Treatment

Ephmeroporus quasimodo sp. nov.

( Figures 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Ephemeroporus sp. ( Sousa & Elmoor-Loureiro, 2012; Sousa et al. 2013).

Etymology. The species name is derived from the fictional character “ Quasimodo ”, the deformed hunchback from the novel Notre-Dame de Paris (Our Lady of Paris) by Victor Hugo.

Type locality. Lagoa do Henrique, a small pond situated in Brasilia National Park, Federal District, Brazil (15.688333°S, 47.940583°W). The type series was collected on 27.05.2002 by L.M.A. Elmoor-Loureiro.

Type material. Holotype. An adult parthenogenetic female, MZUSP 30277. The label of holotype is: " Ephmeroporus quasimodo sp. nov., 1 parth. ♀ from Brasilia, DF, Brazil, HOLOTYPE ".

Paratypes. five parthenogenetic females from the type locality, MZUSP 30278; five parthenogenetic females, MNRJ 23909; five parthenogenetic females from the type locality, EL02476; several females and males from the type locality, EL00516.

Other material studied. 1) A juvenile female from the type locality, sampled on 0 1.11.1980 by L.M.A. Elmoor-Loureiro, slide EL01303; 2) a parthenogenetic female, from a murundus wet campo, located in Brasilia National Park, Federal District (15.778333°S, 47.976111°W), sampled on 17.vii.2009 by GEEA, EL01682; 3) two parthenogenetic females, from Lagoa Joaquim Medeiros, Federal District (15.637750°S, 47.691528°W), sampled on 10.03.2009 by GEEA, EL02346; 4) two parthenogenetic females, from Lagoa Cabocla, Centro de Instruções de Formosa, Goiás (15.793594°S, 47.255447°W) sampled on 18.02.2009 by GEEA, EL01737; 5) six parthenogenetic females, from Lagoa Grande, Centro de Instruções de Formosa, Goiás (15.833136°S, 47.232060°W) sampled on 0 7.08.2009 by GEEA, EL01679; 6) a parthenogenetic female, from a pond in the Chapada dos Veadeiros National Park, (14.074028°S, 47.661306°W), Município de Alto Paraíso, Goiás, sampled on 14.03.2013 by GEEA; 7) a parthenogenetic female, from Lagoa do Formoso, Trijunção Farm (14.817278°S, 45.976583°W), Município de Cocos, Bahia, Brazil, coll. on 26.04.2003 by L.M.A. Elmoor-Loureiro.

Diagnosis. Female. Body high, almost pentagonal in lateral view, not compressed laterally, except at dorsal margin, with high keel. Maximum height at the middle of the dorsal keel. Postero-ventral angle with a tooth, followed by groups of submarginal crescent spinules. Carapace with 15–18 longitudinal lines, anastomosed posteriorly, and with few closed cells on anterior-ventral margin. Head elongated and narrow, rostrum of moderate size, pointed, protruding downwards. Ocellus small, eye two times larger than ocellus. Head shield little longer than wide (width/length 0.8); posterior margin round when flattened. A single median pore is present in juveniles, being absent in adults. Labral keel triangular, convex, with pointed apex, height/width ratio about 2.8, without teeth or setae; close to the apex, a small incision. Postabdomen typical for the genus, except for a narrower postanal portion. Post-anal margin with 2–3 proximal denticles longer and slenderer than the following 6–8, which are crescent distally, and a small denticle on posterior margin; laterally, 4–5 fascicules of short spinules. Postabdominal claw with two basal spines, the basal one very short, and a flagellum in subterminal position. Antennule does not reach tip of the rostrum. Antenna short, basal segment robust with a very small spine; branches relatively slender and similar in size; antennal formula 0(1)-0-3(1)/0-1-3(1); one seta on exopod apical segment about 0.8 the length of the others, on apical segment of endopod one seta thin and less then 0.5 the length of the others; spine on basal segment of exopod reduced, like a spinule; spines on apical segments short. Limb I: ODL strongly tapered distally, with a single seta; IDL with three setae, seta 1 about 1/3 long as seta 3, seta 2 of intermediate size; endite 3 with with an anterior and three posterior setae subequal in length; endite 2 with a naked anterior seta and three posterior setae of different size and armature; endite 1 with a naked anterior seta and four 2-segmented setae, setulated in distal part; ejector hooks similar in size; maxillar process with a short setulated seta. Limb II: Exopodite with a long seta; eight scrapers finely denticulated, scraper 8 little more robust than the others; gnathobase with four elements; filter plate with eight setae, the posterior-most members clearly shorter than others. Limb III: Exopodite elongated, rectangular, with seven setae, seta 4 being the longest; distal endite with three slender and sharp setae, with a cylindrical sensillum located between their bases; basal endite with four stiff setae and one bottle-shaped sensillum, with a long neck; five soft setae on inner portion; gnathobase with three elements; filter plate III with eight setae. Limb IV: Exopodite rectangular, with apex expanded, seven setae, setae 1–5 plumose, seta 6 with sparse long setules at base and dense short setules on distal part, seta 7 with armature hardly visible; inner portion of limb IV with four setae and bottle-shaped sensillum; scraping seta spatulated, three slender flaming-torch seta similar in size, possessing long setules with enlarged bases; four soft setae; gnathobase with a geniculated seta and a cylindrical sensillum; filter plate IV with six setae. Limb V: Exopodite rectangular, not divided into two lobes, with four plumose setae; inner limb portion as a long and setulated lobe; at inner face, two setae of different sizes, densely setulated in distal part; gnathobase with two small elements; filter plate with four setae. Length 0.29–0.40 mm, height 0.27–0.39 mm.

Description. Parthenogenetic female. General. Body high, almost pentagonal in lateral view, not compressed laterally ( Fig. 1 View FIGURE 1 A; 2A–D; 5A–B). Dorsal margin with a high dorsal keel, postero-dorsal angle expressed, round. Maximum height at the middle of the dorsal keel, height/length ratio 1.01 for adults (0.94 for the single juvenile mesaured). Ventral margin convex, with about 54 setae: the first seven setae marginal, next 13–15 marginal and very short, as a series of serrated expanded setal bases, ending at ventral bulge ( Fig. 2 View FIGURE 2 E–F); last setae submarginal, long and feathered, the distal-most decreasing in size ( Fig. 2 View FIGURE 2 G). Postero-ventral valve portion with a tooth followed by two to four groups of submarginal crescent and partially merged spinules ( Fig. 5 View FIGURE 5 G). Posterior margin straight, weakly convex, with a series of short submarginal spinules. In some specimens, the last group of spinules somewhat overlap with the submarginal row of short spinules which continues along the posterior margin ( Fig. 5 View FIGURE 5 G). Carapace with 15–18 longitudal lines, anastomosed posteriorly, and with few closed cells on anterior-ventral margin ( Fig. 2 View FIGURE 2 E).

Head elongated and narrow in lateral view, rostrum of moderate size, pointed, protruding downwards. Ocellus small, compound eye two times larger than ocellus. Distance from tip of rostrum to ocellus longer than that between ocellus and eye. Head shield little longer than wide (width/length 0.8), regions anterior and posterior to mandibular articulation about the same size, with maximum width behind mandibular articulation ( Fig. 2 View FIGURE 2 I–J). Rostrum pointed ( Fig. 2 View FIGURE 2 H). Posterior margin round when flattened ( Fig. 2 View FIGURE 2 J); posterior margin appears conical when not flattened ( Fig. 2 View FIGURE 2 I). Head pores absent in adults. In juveniles, a single median pore is present ( Fig. 2 View FIGURE 2 C–D).

Labrum ( Fig. 3 View FIGURE 3 A–B). Labral keel triangular, convex, with pointed apex, height/width ratio about 2.8, without teeth or setae. A small incision located close to apex,

Antennule ( Fig. 3 View FIGURE 3 C) moderate, cylindrical, abruptly narrowed at the base. Length about three times width, ending about 2/3 its length before the tip of rostrum. Antennular seta thin, of about half length of antennule, arising at 2/3 distance from the base. Nine terminal aesthetascs of different size, reaching the tip of rostrum.

Antenna short ( Fig. 3 View FIGURE 3 D–E), exceeding the tip of rostrum, but not reaching the labral apex. Basal segment robust with a very small spine. Branches relatively slender and similar in size, with basal segments two times longer than middle and apical segments. Antennal formula: 0(1)-0-3(1)/0-1-3(1). Two setae on apical segment of exopodite (1–2) of similar morphology, long, and third seta (3) about 0.8 the length of the others. Two setae (5–6) on apical segment of endopodite long, and one seta thin and much smaller (7), less then 0.5 the length of the others. Seta on penultimate segment of the endopodite (4) long, extending up to the tip of the distal ones. Setae 3, 6, and 7 have both segments unilaterally armed with fine setules; setae 1–2 and 4–5 are bilaterally armed on basal segment and unilaterally armed on distal segment. Spine on basal segment of exopodite reduced in size, looks like a very small spinule. Spines on apical segments short, about 1/2 length of the segment.

Mandibles with asymmetrical molar surfaces.

Thoracic limbs: five pairs. Limb I ( Fig. 4 View FIGURE 4 A–E; 4S). Epipodite small, ovoid, with a long finger-like projection. Accessory seta not seen. ODL strongly tapered distally, its seta with thin setules in distal portion. IDL with three setae ( Fig. 4 View FIGURE 4 B) and a group of about seven very short spinules. IDL seta 1 about 1/3 as long as seta 3, with setules somewhat stronger than setules on setae 2 and 3, which are thin. Seta 3 slightly longer than ODL seta, seta 2 about 2/3 length of seta 3. Endite 3 with with an anterior (1) and three posterior setae (a–c) subequal in length. Endite 2 with a naked anterior seta and three posterior setae (e–f) of different size and armature: seta d stout, with short setules; seta e with distal part more stout than seta d, with robust setules at base; seta f finely feathered, shorter and less robust than the other two ( Fig. 4 View FIGURE 4 C–E). Endite 1 with a naked anterior seta and four 2-segmented setae (g–j), setulated in distal part. Eight rows of long setules on ventral face of limb, the most distal with more numerous setules. Two ejector hooks similar in size. Maxillar process with a densely setulated seta ( Fig. 4 View FIGURE 4 F).

Limb II ( Fig. 4 View FIGURE 4 G–H; 4T). Epipodite ovoid, with a short projection. Exopodite elongated with a long seta. Eight scraping spines finely denticulated; scraper 2 shorter than scrapers 1 and 3, which are similar in size; scrapers 4 to 8 decreasing in length towards gnathobase, with the exception of spine 6, which is the shortest one; scraper 8 little more robust than the others. Distal armature of gnathobase with four elements, one very small near the base of the others, the largest setulated in distal part and the two others shorter and naked. Filter plate II with eight setae, the dostal-most members clearly shorter than others.

Limb III ( Fig. 4 View FIGURE 4 I–M; 4T). Epipodite small, ovoid, with a long finger-like projection. Exopodite elongated, rectangular, with seven setae. Seta 4 the longest, setae 1–2 subequal, little shorter than seta 4, seta 3 about 1/2 seta 4, setae 5–6 subequal in length, about 2/3 length of seta 7. Setae 3–7 plumose, setae 1–2 not plumose, with short thin setules in distal part; seta 1 with few setules in basal part. Distal endite with 3 setae slender, sharp, armature of first two hardly visible, seta 1 long, seta 2 about ½ seta 1 length, seta 3 short, less than ½ seta 2 size; cylindrical sensillum located between their bases. Basal endite with four stiff setae (4–7) and a bottle-shaped sensillum, with a long neck, close to gnathobase ( Fig. 4 View FIGURE 4 L). Five soft setae on inner portion increasing in size basally. Gnathobase with a dense group of setules; distal armature with three elements: two elongated, narrowing distally sensilla, and a geniculated seta densely setulated. Filter plate III with eight setae.

Limb IV ( Fig. 4 View FIGURE 4 N–Q; 4T). Epipodite small, ovoid, with long finger-like projection. Exopodite rectangular, with expanded apex and bearing seven setae. Setae 5–7 similar in size; setae 1 and 3–4 about the same length, seta 3 slightly short, about ¾ of seta 5; seta 3 as long as seta 5. Seta 1 with armature hardly visible; seta 2 with sparse long setules at base and dense short setules on distal part; setae 3–7 plumose. Inner portion of limb IV with four setae and a small sensillum; a hillock between the first seta and the sensillum ( Fig. 4 View FIGURE 4 P). Scraping seta spatulated (seta 1), three slender flaming-torch seta similar in size (setae 2–4), each with about 8–10 long setules; especially on first flaming torch, setule bases enlarged. Four soft setae on inner limb portion. Gnathobase with a geniculated twosegmented seta and a bottle-shaped sensillum near base ( Fig. 4 View FIGURE 4 Q). Filter plate IV with six setae.

Limb V ( Fig. 4 View FIGURE 4 R–T). Pre-epipodite setulated. Epipodite small, ovoid, with long finger-like projection. Exopodite rectangular, not divided into two lobes, with four plumose setae, with length gradually decreasing basally. Inner limb portion as a long lobe ( Fig. 4 View FIGURE 4 S), with setulated inner margin. At inner face, two setae densely setulated in distal part, the first longer and the second of same length as exopodite seta 1. Gnathobase with two small elements. Filter plate with four setae.

Postabdomen ( Fig. 2 View FIGURE 2 K–L) large (postabdominal length/total length about 0.43), elongated, postanal portion narrow (height/length <40%). Pre-anal angle prominent; distal angle rounded and prominent. Post-anal margin with 2–3 proximal denticles longer and slender than the following 6–8, which are crescent distally, and a small denticle on posterior margin; laterally, 4–5 fascicules of 6–10 short spinules. Anal margin is armed with a group of four robust and long spinules, and fascicules of 4–5 spinules, continuing along to the pre-anal angle. Postabdominal claw of moderate length. Two basal spines, the proximal one very short, less than 0.25 the distal one, which is about 0.3 of the claw length. Along internal and external sides of the claw, a series of spinules becoming distally more robust. A flagellum in subterminal position.

Ephippial female and ephippium. ( Fig. 1 View FIGURE 1 B; 5H–I). Ephippial female larger than parthenogenetic female (up to 0.44 mm; height up to 0.38 mm), Height/length ratio 0.90, with maximum height at articulation between carapace and head shield, then progressively decreasing to dorsal posterior angle. Ephippium brown, surface marked by polygons and punctuated ( Fig 5 View FIGURE 5 H–I), with a single egg.

Male. ( Fig. 1 View FIGURE 1 C; 3H–K). General. In lateral view, similar to parthenogenetic female, with maximum height at the middle of the dorsal keel, but less high than females (height/length ratio about 0.89).

Antennule shorter than in female (length/width about 2.6), with nine terminal aesthetascs of same size. Antennular seta and male seta both arising at 2/3 distance from the base ( Fig. 3 View FIGURE 3 I). Male seta about 0.8 length of antennule.

Limb I with U-shaped copulatory hook ( Fig.3 View FIGURE 3 K), with two incisions at its tip. Male seta straight and pointed. The copulatory brush setae less than ½ the male seta. Ventral face of the limb under the copulatory brush with four rows of setules.

Postabdomen with marginal denticles and preanal and distal angles well-expressed; the sperm ducts open laterally close to insertion of the claw ( Fig. 3 View FIGURE 3 J). Postabdominal claw similar to that in female.

Size. Length of single studied juvenile female I (with a head pore) 0.29 mm, height 0.27 mm. In adult females, length 0.30–0.40 mm, height 0.30–0.39 mm. In adult males, length 0.25–0.27 mm, height 0.23–0.24 mm.

Differential diagnosis Ephmeroporus quasimodo sp. nov. clearly differs from all other species of the genus in the high dorsal keel (hunchback), and other unique characters. Another diagnostic character is the smooth labral keel, without crenulations or teeth, but with a small incision near the apex. According to original description, Ephemeroporus poppei (Richard, 1897) does not present any teeth, incisions, or crenulations on the ventral margin of the labrum, and the posterior-ventral angle of the carapace lacks a tooth. Therefore, although having similar labral keel, E. quasimodo sp. nov. differs from E. poppei in the presence of a well-defined tooth on the valve. The postero-ventral angle with a tooth also distinguishes the new species from Ephemeroporus acanthodes Frey, 1982 , Ephemeroporus tridentatus (Bergamin, 1939) , and Ephemeroporus phintonicus (Margaritora, 1969) .

The smooth labral margin distinguishes E. quasimodo sp. nov. from the other Ephemeroporus species with teeth on the postero-ventral angle of the valve: Ephemeroporus archboldi Frey, 1982 , Ephemeroporus barroisi (Richard, 1894) , and Ephemeroporus laevis ( Sars, 1904) with three or four teeth or crenulations; Ephemeroporus epiaphantoii Alonso, 1987 and Ephemeroporus margalefi Alonso, 1987 , have four pairs of teeth; and Ephemeroporus hybridus (Daday, 1905) possess a single and well-defined tooth at the middle of the labral keel.

The valve of E. quasimodo sp. nov. is marked by 15–18 striae, with very few closed cells, a character that allows to differ it from other species. Only E. hybridus presents similar carapace sculpture, but with fewer striae (c. 12). The remaining species are totally or predominantly marked by closed hexagonal cells.

Ephemeroporus quasimodo sp. nov. is a large species, in comparison with the majority of species, which do not reach 0.40 mm (data from Sars 1904; Paggi 1983; Frey 1982; Alonso 1987; Smirnov 1996). Only E. archboldi View in CoL , with size up to 0.49 mm, is larger than the new species.

Based on the images from literature, the post-anal part of E. quasimodo sp. nov. seems to be slenderer than observed in other species of the genus. In the present species, the relation height/length is less than 40%, while for species with image available this relation is always over 48%.

The postabdomen of the E. quasimodo sp. n. male is not very modified in comparison to the one of the female, preserving marginal spines, which are also observed in E. epiaphantoii View in CoL , E. tridentatus View in CoL , and E. barroisi View in CoL (respectively, Alonso 1987; Paggi 1983; Yalim & Çiplak 2010). Conversely, the male postabdomen has modified shape and marginal spines which have been reduced to spinules in E. phintonicus View in CoL and E. margalefi ( Alonso 1996) View in CoL .

Distribution and ecology. The known populations of E. quasimodo sp. nov. occur in small shallow ponds in Central Brazil, with dense coverage of macrophytes, surrounded by typical "Cerrado" vegetation (tropical savanna). In addition to specimens studied in this paper, E. quasimodo sp. nov. was also recorded from Lagoa do Exército, in Brasilia National Park ( Sousa & Elmoor-Loureiro, 2012, as Ephemeroporus sp). These ponds are characterized by a slightly acid waters (pH 4.9–7.0), with low conductivity (2.7–9.0 mS/cm) and nutrient concentrations typical of oligotrophic ecosystems (total phosphorus 3.2–33.7 µg/L; total nitrogen 1.0–179.6 Μg/L). Low values for electrical conductivity and nutrient concentrations have been considered as indicative of pristine or natural conditions for the Cerrado’s aquatic systems ( Padovesi-Fonseca & Martins-Silva 2012; Fonseca et al. 2014).