Bergamina lineolata Sars 1901, comb. nov.
Creators: name: Elmoor-Loureiro, Lourdes M. A.
name: Santos-Wisniewski, Maria José
name: Rocha, Odete
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Branchiopoda
Diplostraca
Chydoridae
Bergamina
Bergamina lineolata

description: Bergamina lineolata (Sars, 1901) comb. nov.
(Figs. 1–4)
Etymology. The genus is named in honor of Dr Francisco Bergamin, the first Brazilian cladocerologist, who lived in São Paulo, the type locality of the present taxon.
Type locality. Small farm pond at Pradópolis, São Paulo state, Brazil (21° 20.624’ S; 48°07.125' W), sampled on 18/12/1999, by M.J. Santos-Wisniewski. Water body characteristics: about 1.0 m deep; transparency 0.2 m (Secchi Disk); pH 6.01; dissolved oxygen 1.02 mgL -1; water conductivity 205 µScm -1; total phosphorus 764.45 µg L -1; covered by Eichhornia azurea.
Type material. Neotype. One adult female preserved with ethanol 70% and glycerol (1%) deposited at Zoological Museum of São Paulo University (MZUSP 15547).
Paraneotypes. The remaining specimens (19) are deposited at Universidade Católica de Brasília (EL01568, slides EL01569, EL01570 and EL02307) and Universidade Federal de Alfenas, MG.
Diagnosis. Body subquadrate, with maximum height in middle, bilaterally compressed. Postero-dorsal and postero-ventral angles rounded, posterior margin convex, ventral margin straight to slightly concave in the middle, anterior margin concave. Conspicuous parallel striation on the carapace, curved on the anterior portion. Head relatively small, with rostrum short, quadrate with round angles. Ocellus slightly smaller than eye. Three major head pores with a relatively narrow connection between them, located close to the posterior margin. Labrum with labral keel large, triangular, without setulation or denticles. Antennule short, almost reaching tip of rostrum; antennular sensory seta slender, as long as antennule; nine aesthetascs of different size, longest little longer than antennule, projecting beyond tip of rostrum. Antenna relatively short, exopod shorter than endopod, all segments cylindrical; setal formula (endo/exo) 113/003, spinal formula 001/101; one of the terminal setae on endopod much shorter than the others. Mandibles elongated, asymmetrical, and articulated close to the headshield margin. Postabdomen large and oblong, with long postanal portion, slightly narrowing distally. Preanal margin short, somewhat longer than anal margin. Preanal angle evident, postanal not well defined. Postanal dorsal margin provided with about nine groups of spinules in which the most distal one is stronger (at least in most distal groups). Distal dorsal angle round and protuberant, with three spines, accompanied by 0–2 spinules. Lateral fascicles with very delicate spinules. Postabdominal seta naked in proximal portion, and bisetulated, with long setules, on distal one. Postabdominal claw slightly and evenly curved. Basal spine very short, formed by spinules partially merged.
Five trunk limbs. Limb I: small epipodite, ovoid. Accessory seta short. Ejector hooks of equal size. ODL with a long, naked seta. IDL with two setae shorter than ODL seta, armed with fine setules. Endite 1 with three soft twosegmented setae, decreasing in size basally. An anterior naked and very long seta (ans) between endites 1 and 2. Endite 2 with three soft setae of unequal size. Endite 3 with three soft setae of similar size and an anterior seta. Limb II: Epipodite ovoid. Exopodite a elongated lobe without seta. Eight scrapers, armed by fine setules, and decreasing in size basally, except for scraper 5, which is longer that 4. A series of hillocks posteriorly to scrapers. Gnathobase with three elements, one of them bifurcated; filter plate with seven setae, two distalmost setae markedly short. Limb III: Exopodite subquadrangular, with six setae; seta 3 is the largest, being asymmetrically setulated on distal segment. Distal endite with three stiff setae, the most proximal more delicate than the others. Basal endite with five setae. Four posterior soft setae. Four gnathobasic elements, one of them a thick sensillum. Seven setae in filter plate. Limb IV: Epipodite ovoid. Exopodite large, rounded to elongated, with six setae, being seta 3 much longer than the others. Inner limb face with a sensillum, a scraping seta and three flaming-torch setae. Posteriorly, three soft setae. Gnathobase with four elements: a sensillum, two short elements and a seta of moderate size. Filter plate with five setae. Limb V: Epipodite ovoid, with a finger-like projection. Exopodite large, suboval, not separated in two lobes, with a single distal seta and three lateral setae. Inner limb portion with wide flap-like distal projection, fringed by setules. Two short submarginal setae on inner face of limb. Gnathobase greatly reduced.
Description. Parthenogenetic female. General: In lateral view body subquadrate (body height/body length 0.66-0.68 in adults, n=10), with maximum height in middle (Fig. 2 A). In dorsal view, body bilaterally compressed. Dorsal margin regularly arched, postero-dorsal and postero-ventral angles rounded, posterior margin convex, ventral margin straight to slightly concave in the middle, anterior margin concave. Conspicuous parallel striation on the carapace, without secondary striae between them (Fig. 4 C). Colour, after fixation, whitish to pale yellow.
Head (Fig. 2 B–D) relatively small, with rostrum short, quadrate with round angles. Ocellus slightly smaller than eye and located approximately in middle of distance from eye to tip of rostrum. Head shield with mandibular articulation of alonine-type. Three major head pores with a relatively narrow connection between them (Fig. 2 C), located close to the posterior margin (IP/PP about 2). Lateral head pores were not seen, even in SEM micrographs (Figs. 4 A–B).
Labrum (Fig. 2 E) with small distal labral plate and a large medial labral keel, without lateral projections. In lateral view, labral keel triangular, without setulation or denticles.
Valves large, subovoid (Fig. 2 F), sculptured with 16–17 delicate, curved striae, parallel to the dorsal margin, but curved on the anterior part of the valves. Anterior margin concave (Fig. 2 G). About 27 setae on ventral margin. Setae divisible in four groups, from anterior to posterior: 5 long marginal, 7 short marginal, 9 long submarginal (Fig. 2 H), and 4 decreasing marginal setae. Posterior margin of valve with a row of numerous short setules, implanted on inner side of carapace (Fig. 2 I).
Postabdomen (Figs. 2 J, 4D) large and oblong, with long postanal portion (2.0–2.5 times the preanal portion; about 3 times the anal groove). Ventral and dorsal margins straight to slightly convex, slightly narrowing distally. Anal margin relatively short, with lateral groups of spinules. Preanal margin somewhat longer than the anus. Preanal angle evident, but postanal not well defined. Postanal dorsal margin provided with about nine groups of spinules in which the most distal one is stronger (at least in most distal groups). Distal dorsal angle round and protuberant, with three spines, accompanied by 0–2 spinules. Lateral fascicles with very delicate spinules (not reported by Sars).
Postabdominal seta (Fig. 2 J): approximately half long as the postabdomen. Proximal portion naked, distal portion bisetulated, with long setules. Postabdominal claw (Fig. 2 K): approximately as long as pre-anal margin, slightly and evenly curved. Dorsal side with two groups os spinules, the basal one increasing in size distally. Basal spine very short, length less than the half claw diameter at base. In fact, the basal spine consists in a series of 4–5 spinules, partially merged (Figs. 4 E-F).
Antennule (Fig. 2 L) short, almost reaching tip of rostrum. Antennular sensory seta slender, as long as antennule length, arising at distance of one-third of antennule length from distal end. Nine aesthetascs of different size, longest little longer than antennule, projecting beyond tip of rostrum.
Antenna (Fig. 2 M) relatively short. Antennal branches relatively elongated, exopod shorter than endopod, all segments cylindrical. Setal formula (endo/exo) 113/003, spinal formula 001/101. One of the terminal setae on endopod much shorter than the others. Spine on first (basal) segment of exopod about half long as second segment; apical exopod spine of same size. Apical endopod spine little longer than the exopod one.
Mandible elongated, with head not widened (Fig. 2 N). Left and right mandibles asymmetrical. Mandibles articulation close to the headshield margin.
Five trunk limbs. Trunk limb I (Figs. 3 A–E). Epipodite small, ovoid. Accessory seta short. Two ejector hooks of equal size anteriorly on outer portion of limb corm. ODL with a long, naked seta (Fig. 3 B). IDL of similar size as ODL, with two setae shorter than ODL seta, and somewhat different in size, armed with fine setules unilaterally in terminal half. Endite 1 with three soft two-segmented setae (1–3), setulated, and decreasing in size basally. An anterior naked and very long seta (ans) between endites 1 and 2 (slightly longer than seta 5). Endite 2 with three soft setae of unequal size (4–6): seta 4 assymetrically armed with short and long setules, seta 5 the longest, asymmetrically armed with long setules proximally, seta 6 short, armed bilaterally with short setules. Endite 3 with three soft setae of similar size (7–9), all armed with short hairs bilaterally, and an anterior seta (10). Ventral face of the limb with two series of long setules and two with short setules; groups of fine spinules on ODL and IDL. Maxillar process with a single seta densely setulated.
Trunk limb II (Figs. 3 F–I). Epipodite ovoid. Exopodite a elongated lobe with a row of short setules, without seta. Eight scrapers, armed by fine setules; scrapers 1 to 4 decreasing in size basally; scraper 5 longer that 4, similar in size to scraper 3; scraper 5–8 again with size decreasing basally. A series of hillocks posteriorly to scrapers. Gnathobase with prominent basal-ventral angle, armed with relatively long setules. Distal armature of gnathobase with three elements, one of them bifurcated; filter plate with seven setae, two distal-most setae markedly short.
Trunk limb III (Fig.3 J). Exopodite subquadrangular, with six setae; seta 1–2 plumose, being seta 2 the smallest; seta 3, the largest exopodite seta, with basal segment bisetulated and distal segment asymmetric (one side with fine, short and spaced setules; the opposite side with long and strong setules, not reaching the end); seta 4 short (little shorter than seta 1), plumose only at distal part, the basal part unisetulated; seta 5 plumose, with short setules; seta 6 about the same size of seta 2, but slender and apparently naked. Distal endite armed with three stiff setae, the most proximal much more delicate than the others. Basal endite of similar size with distal endite, anteriorly with five setae. Four posterior soft setae, setulated bilaterally. Distal armature of gnathobase with four elements, one of them a thick sensillum. Seven setae in filter plate III.
Trunk limb IV (Figs. 3 K–M). Epipodite ovoid. Exopodite large, rounded to elongated, with six setae; exopodite setae 5 and 6 markedly slender than the others; seta 3 much longer than the others (setae 1–4), which are plumose. Marginally on inner limb face, a row of four setae and a sensillum: seta 1 (scraping seta) longest, stout, naked; setae 2–4 armed with fine setules (flaming-torch setae), decreasing in size basally, seta 4 shortened. Posteriorly, three soft setae. Distal armature of gnathobase with four elements: a sensillum, two short elements and a seta of moderate size. Filter plate with five setae.
Trunk limb V (Fig. 3 N). Pre-epipodite relatively large; epipodite ovoid, with a finger-like projection. Exopodite large, suboval, with four plumose setae, a single distal (seta 4) and three lateral (setae 1–3). Inner limb portion with wide flap-like distal projection, fringed by setules. Two short submarginal setae (1’–2’) on inner face of limb. Gnathobase greatly reduced, no filter plate was found.
Size. Up to 0.37 mm.
Differential diagnosis. Bergamina gen. nov. is an Alona -like species that belongs to the Coronatella -branch (Van Damme & Dumont 2008b), sharing with this group the presence of five pairs of trunk limbs, six setae on the exopodite of the third limb, and unmerged spines on postabdomen. However, Bergamina gen. nov. presents a unique combination of characters: 1) flattened and quadrangular shape; 2) three main head pores; 3) alonine-like mandibular articulation; 4) two finely setulated setae on IDL and a long anterior seta on endite 1 of the first limb; 5) second limb without exopodite seta; 6) third limb with six setae on exopodite; 7) fourth limb with three flamingtorch on endite; 8) exopodite of the fifth limb not separated in two lobes; 9) postabdomen long, postanal portion three times long as the anal margin, with three marginal spines on distal end, followed by groups of fine setules; 10) basal spine very short.
Morphological differences with Alona and members of the Coronatella -branch are detailed in Table 1. The peculiar postabdomen shape and armature, which are not observed in any other genus of the Coronatella -branch, are the more noteworthy features of Bergamina gen. nov. Another remarkable character of the new genus is the long anterior seta on endite 1 of the first limb; although other Aloninae genera, such as Miralona and Leydigiopsis, can present such seta, these are never as long as in Bergamina gen. nov.
description: Published as part of Elmoor-Loureiro, Lourdes M. A., Santos-Wisniewski, Maria José & Rocha, Odete, 2013, Redescription of Alonella lineolata Sars, 1901 (Crustacea, Cladocera, Chydoridae) and its translocation to the subfamily Aloninae and to the new genus Bergamina gen. nov., pp. 571-581 in Zootaxa 3630 (3) on pages 572-578, DOI: 10.11646/zootaxa.3630.3.11, http://zenodo.org/record/218619