Notodiaptomus carteri (Lowndes, 1934)

Perbiche-Neves, Gilmar, Boxshall, Geoffrey Allan, Previattelli, Daniel, Nogueira, Marcos Gomes & da Rocha, Carlos Eduardo Falavigna, 2015, Identification guide to some Diaptomid species (Crustacea, Copepoda, Calanoida, Diaptomidae) of " de la Plata " River Basin (South America), ZooKeys 497, pp. 1-111 : 24-28

Taxon classification Animalia Calanoida Diaptomidae

Notodiaptomus carteri (Lowndes, 1934) Figs 29, 30, 31

Diaptomus carteri Lowndes, 1934

Diagnosis.

Adult male, body length 1484 µm. Modified seta on segment 13 of A1R reaching distal end of segment 14 (Fig. 29A). Right BspP5 with longitudinal groove in surface, ornamented with small surface granulations (Fig. 29C). Right Exp2P5 with slightly outwardly curved lateral spine inserted on distal margin of segment, length about 1/3 of terminal claw; insertion of lateral spine separated from base of terminal claw by gap barely greater than basal width of spine (Fig. 29B, C).

Adult female, body length 1770 µm. Ped4 and Ped5 separated by incomplete suture; process present on mid-dorsal surface of Ped4 (Fig. 30A, C); lateral wings slightly asymmetrical, with two pairs of sensillae on each side; internal sensilla of right side thin, setule-like; left sensilla slightly larger than right. GS asymmetrical, about 1.5 times longer than wide, swollen anteriorly (Fig. 30C), swelling on left side greater than that on right margin; left side swelling hemispherical, bearing single posterolaterally-directed sensilla; swelling on right side with projecting semi-circular lobe with posteriorly-directed sensilla. Right distal margin of GS longer than left, each side with rounded process at posterior end. P5 symmetrical (Fig. 30B) with small conical process at distal corner of Cx bearing short and triangular sensilla, about as long as wide. BspP5 with outer seta barely reaching middle of outer margin of Exp1P5. EnpP5 one-segmented, reaching 2/3 distance along inner margin of Exp1P5. ExpP5 3-segmented; lateral spine of Exp2P5 short, about as long as outer margin of Exp3P5; external seta of Exp3 about half length of internal seta; internal seta reaching middle of terminal claw.

Remarks.

The illustrated specimens were collected from the lower Paraná River (RPAR-L2). The body length is slightly larger than the known range for males, 1315 to 1439 μm, given by Ringuelet and Martínez de Ferrato (1967). These authors published the first record from Argentina, near Santa Fe (equivalent to site RPAR-M3 in this study, Fig. 1), and they associated this species with the presence of floating aquatic macrophytes. The original description of this species ( Lowndes 1934) was based on material from Paraguay, collected in flooded regions and wetlands, typically where there are macrophytes. In the present study the records of this species (Fig. 31) were about 500 km downstream from the locality sampled by Ringuelet and Martínez de Ferrato (1967). Santos-Silva (2008) provided records of this species from Paraguay, Argentina and southern Brazil, in the Patos Lagoon. Ringuelet and Martínez de Ferrato (1967) provided physical and chemical data for the water in the ponds where they found this species. Given the range of sites reported in this study, we infer that this species can occur in a wide range of habitat types.

Females of Notodiaptomus carteri can be readily distinguished from congeners by the asymmetrical swellings of the genital double-somite.