Notodiaptomus iheringi (Wright, 1935)

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 : 42-47

Taxon classification Animalia Calanoida Diaptomidae

Notodiaptomus iheringi (Wright, 1935) Figs 55, 56, 57, 58, 59, 60

Diaptomus iheringi Wright, 1935

Diagnosis.

Adult male, body length 922 µm. Posterior margin of Ped3 ornamented with rows of spinules; Ped4 and Ped5 ornamented with spinule rows along posterior margins and on lateral surfaces (Fig. 56 B–F). Rostral filaments asymmetrical (Fig. 56A). Single row of spinules present on first segment of A1R (Figs 55D, 56G, H); modified seta on segment 13 of A1R strong, with minutely bifid apex, reaching beyond level of insertion of proximal seta on segment 14 (Fig. 55A); spinous process of segment 15 longer than spinous process of segment 16) (Fig. 57A, B). Enp1 of A2 ornamented with pore and spinule row (Figs 55G, 56I). Cx of P1 with setules on outer surface (Fig. 57E). Right and left internal margins of P5 without sclerotized processes (Figs 55B, C, 57G). Right BspP5 with irregular oblique fissure on middle of surface; distal part of fissure ornamented with small surface granulations; external seta inserted distally on lateral margin. Lateral spine on right Exp2P5 inserted in distal third of external margin, length about 1/6 (16%) of length of terminal claw (Figs 55E, F, 57C, D, F, G).

Adult female, body length 1093 µm. Incomplete suture present between Ped4 and Ped5 with plane of fusion marked by transverse row of strong spinules, with double row in middle section of dorsal surface (Figs 58A, 59D); lateral surfaces of posterior prosomal somites ornamented with spinules (Fig. 59F). Lateral wings bearing two unequal sensillae; large sensilla located at apex about 1.5 times longer than wide. GS asymmetrical, about 1.3 to 1.4 times longer than wide; dilated anteriorly, swellings of similar size; left swelling hemispherical; both swellings bearing sensilla approximately 2.5 times longer than wide, right sensilla inserted on dorso-lateral surface and not on apex of swelling (Figs 58A, 59A). P5 symmetrical (Fig. 58B) with small conical process at outer distal corner of Cx bearing short, robust triangular sensilla, about 1.1 times longer than wide. BspP5 with long external seta, extending beyond distal end of external margin of Exp1P5 (Fig. 58B). EnpP5 one-segmented (Fig. 59C, G), about 3/4 length of internal margin of Exp1P5. Exp 3-segmented; lateral spine of Exp2P5 not reaching end of external margin of Exp3P5; external seta of Exp3P5 approximately 3.5 times shorter than internal seta; internal seta reaching just beyond middle of terminal claw (Fig. 59D).

Remarks.

Our specimens were taken in the Grande River at Furnas Reservoir. In the present study this species was found in southeastern and southern Brazil and in the upper part of the Paraná River basin, with its southerly distribution boundary represented by the Iguaçu River (Fig. 60). Other studies ( Santos-Silva 2008) indicate a widespread distribution in Brazil, and the type locality is in Paraiba State in northeastern Brazil, but it also occurs in some parts of northern Argentina. This species can be confused with its congeners Notodiaptomus cearensis and Notodiaptomus isabelae (Wright, 1936), but details of the male A1R and P5 are useful to distinguish Notodiaptomus iheringi from these other two species. This species also resembles Notodiaptomus conifer in possessing a small lateral spine on the P5, but Notodiaptomus conifer has a well-developed spinous process on segment 15 of A1R (Fig. 35A), which is much larger than that of Notodiaptomus iheringi (Fig. 55A). In the present study this species occurred in a variety of habitats with different trophic states, from oligotrophic, such as the Emborcação and Furnas reservoirs, to the eutrophic Barra Bonita and Foz do Areia reservoirs. Its presence or absence, therefore, is not indicative of trophic status and this species is not suitable for biomonitoring purposes.