Heteromurus (Heteromurtrella) nitens Yosii, 1964

Katz, Aron D., Taylor, Steven J., Soto-Adames, Felipe N., Addison, Aaron, Hoese, Geoffrey B., Sutton, Michael R. & Toulkeridis, Theofilos, 2016, New records and new species of springtails (Collembola: Entomobryidae, Paronellidae) from lava tubes of the Galapagos Islands (Ecuador), Subterranean Biology 17, pp. 77-120 : 82-84

Heteromurus (Heteromurtrella) nitens Yosii, 1964 Figs 5, 6

Descriptive notes.

Color. Background color white (Fig. 5A), with orange granules scattered across head and body.

Head. Apical pin seta on Ant. IV present (Fig. 5B). Dorsal chaetotaxy of head as in Figure 5C: row An with 7 or 8 Mc; Mc A0, A2, A3, A4 present, A5 present as mc; row M with Mc M1 and M2 displaced anteriorly, forming cluster with series A, mc M0, M3 and M4 present, 2 additional mc present, including M3p, posterior to M series; row S with 8 Mc, element S1 absent; row Ps with mc Ps2, Ps3, and Ps5; 5 posterior Mc present.

Dorsal body chaetotaxy. Dorsal chaetotaxy of Th. II as in Figure 5D: anterior and medial rows with Mc a5, M1, M2, M4, M4i, M4p; posterior row with 7 Mc. Dorsal chaetotaxy of Th. III as in Figure 5E: with Mc a3, a4, a5, m4, p1, p2 and p3. Dorsal chaetotaxy of Abd. I (Fig. 6A) with 3 Mc (m2, m3, m4). Dorsal chaetotaxy of Abd. II (Fig. 6B) with 2 Mc. Dorsal chaetotaxy of Abd. III (Fig. 6C) with Mc m3 and pm6 present. Dorsal chaetotaxy of Abd. IV (Fig. 6D) with 4 inner Mc; mc T3, ciliate.

Remarks.

The chaetotaxy of the single individual collected (an adult female), is identical to that described for Heteromurus nitens from the Kingdom of Tonga by Yosii (1964). The individual from Galápagos differs from Yosii’s (1964) description only in claw morphology, our specimen lacks the inner unpaired ungual tooth (Fig. 6E). This is the first record of the genus Heteromurus from the Galápagos Islands.

The description above is intended to supplement the original description by Yosii (1964) with detailed descriptions and illustrations of dorsal head and body chaetotaxy. Most scales and setae had fallen off our specimen during transport making it difficult to differentiate elements (i.e., scales, sensilla, microsetae). Therefore, the mc on Th. II-Abd. IV are not illustrated. Some sensilla may have also been omitted from the illustrations if not visible on the specimen.

This species’ peculiar distribution (reported from Tonga and Galápagos) indicates its range extends across the Pacific Ocean and may occur on other Pacific Islands. The difference in number of inner ungual teeth and vast geographical distance separating the populations of Tonga and Galápagos hint at a species level differentiation. However, in view of the general morphological similarity and a lack of sufficient material, we have chosen not to erect a new name for this single individual.

Distribution.

'Eua Island, Kingdom of Tonga ( Yosii 1964) and Isabela Island, Galápagos, Ecuador (new record).

Material examined.

Ecuador, Galápagos, Isabela Island: 1♀ on slide, La Cueva de Sucre, 21.iii.2014 (G. Hoese), INHS Acc. 567,401.