Notodiaptomus dentatus Paggi, 2001

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 : 34-37

Taxon classification Animalia Calanoida Diaptomidae

Notodiaptomus dentatus Paggi, 2001 Figs 44, 45, 46

Diagnosis.

Adult male, body length 1046 µm. Posterior margin of Ped4 ornamented with more or less regular row of spinules (Fig. 44B). Small denticle present on outer margin of external caudal seta, near base (Fig. 44H). Modified seta on segment 13 of A1R well developed with minutely bifid apex, reaching middle of segment 14 (Fig. 44C); segment 20 of A1R variable, with or without falciform process. Right BspP5 1.8 times longer than wide, with longitudinal fissure ornamented with surface granulations. Surface of right Exp3P5 with 3-6 sclerotized processes (Fig. 44A, F, G); lateral spine of Exp2P5R short (Fig. 44A, D, E).

Adult female, body length 1335 µm. Incomplete suture present between Ped4 and Ped5, with spinule row marking plane of fusion (Fig. 45A); row of spinules present dorsally along posterior margin of Ped4 (Fig. 45A); lateral wings of similar size but slightly asymmetrical; two sensillae, one large and one small, present on each wing; apical sensilla on left side located on small projection and with apex directed posteriorly; right sensilla located at apex of projection directed perpendicular to body axis. GS asymmetrical (Fig. 45A), approximately 1.9 times longer than wide. Anterior part slightly dilated, left swelling larger than right one; left side hemispherical, with strong sensilla at apex of swelling, about 1.5 times longer than wide; right side ornamented with sensilla at apex of triangular projection, sensilla about twice as long as wide; posterior to sensillate swelling, external margin sinuous in dorsal view, ending in well-developed lobe at posterior end of right side. P5 symmetrical (Fig. 45B), with small conical process at outer distal corner of CxP5 bearing triangular sensilla, about 1.4 times longer than wide. BspP5 with long outer seta long, reaching almost to end of outer margin of Exp1P5. EnpP5 one-segmented, length exceeding middle of inner margin of Exp1P5. Exp 3-segmented; lateral spine of Exp2P5 just reaching end of external margin of Exp3P5; external seta of Exp3P5 about 1/4 (25%) length of internal seta; internal seta extending almost to tip of terminal claw.

Remarks.

The illustrated specimens were collected from the middle stretch of the Paraná River (Fig. 46, RPAR-M3). The body length of the sampled specimens is slightly less than that reported by Paggi (2001) but falls within the known range for this species. Paggi (2001) highlighted two important characteristics of this species: 1) the presence of sclerotized processes on the surface of the right Exp2P5 of the male, and 2) the presence of a small tooth-like denticle on the outer margin of external caudal seta, near its base. This tooth-like process provides the basis for the etymology of the species.