Ectonura barrai
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Ordo: Poduromorpha
Familia: Neanuridae
Genus: Ectonura
Name
Ectonura barrai Janion & Bedos & Deharveng, 2011 sp. n. – Wikispecies link – ZooBank link – Pensoft Profile
Type material
Holotype male on slide. South Africa: Western Cape, Grootvadersbosch Nature Reserve, Heidelberg, 24/08/2010, Southern Afrotemperate Forest vegetation, in litter, extraction on Berlese funnel, Charlene Janion leg (RSA10_GVB009, 33°59.167'S, 20°48.639'E).
1 male paratype on slide, same data as holotype — 2 paratypes on slides (1 male, 2 juveniles) and 5 paratypes in alcohol, ibid, Grootvadersbosch Nature Reserve, Heidelberg, 24/08/2010, same habitat, extraction on Berlese funnel, Charlene Janion leg (RSA10_GVB008, 33°58.964'S, 20°48.524'E)
Type deposition
Holotype and 4 paratypes (1 male and 1 juvenile on slides, 2 in alcohol) in IM; 5 paratypes (1 male and 1 juvenile on slides, 3 in alcohol) in MNHN.
Description
Length 1.1–1.3 mm (males). Colour white in alcohol. Eyes 2+2, unpigmented, rather large (diameter about 3 times that of Ocm socket, Fig. 5A). Habitus similar to Paleonura (Fig. 4A). No cryptopygy. Secondary granules rather large (the size of a mesochaeta socket). Dorsal tubercles not clearly delimited, only indicated by secondary granules irregularly arranged, without tertiary granules. No reticulations. No plurichaetosis. Ordinary dorsal chaetae differentiated in macrochaetae, mesochaetae and microchaetae (Figs 4A, 6). Dorsal macrochaetae basally swollen, straight or slightly bent, subcylindrical, long, moderately thick, with minute scales sparsed apparently unilaterally, in their distal half, distally sheathed, rounded apically (Figs 5C, D, 6). Dorsal mesochaetae shorter, acuminate to blunt, smooth or weakly rugose. Dorsal microchaetae thin, smooth, less than 1/5 of macrochaetae, present on all tergites (Di2 from Th. II to Abd. V, De3 on Th. II-III, and De2 on Abd. I-V). S-chaetae thin, smooth, acuminate, 2/3 as long as or slightly shorter than closest macrochaeta (Figs 5C, 6).
Ant. I with 7 chaetae, Ant. II with 11 chaetae, Ant. III with 18 chaetae (chaetae d4 and d5 present). Ant. IV organite as a very short thick rod; apical bulb feebly trilobed, fused to Ant. IV tip (Fig. 4B). Buccal cone moderately elongated. Maxilla styliform, mandible thin and bidentate with distal tooth subdivided in 2 or 3 minute cilia. Labrum elongate, rounded and finely denticulated apically, with ventral sclerifications arc-like distally. Labral formula 0/2,4. Labium with 4 basal, 3 distal and 3 lateral chaetae, and 2 minute sphaerical x papillae (Fig. 5B).
Head chaetotaxy as in Table 2A and Fig. 4A. Head with 9 chaetal groups: CL, 2 (½ Af + Oc), 2 DL, 2 (L, So), 2 (Di, De) on very faint tubercles hardly separated on axis. Central area with A, B, D, F, G, Oca, Ocm and Ocp (alternatively, Oca might be homologous of chaeta E). Macrochaeta Ocm internal to ocular line, equally distant from omma; Ocp macrochaeta internal to and at level of posterior omma; Oca antero-internal to Ocm (Fig. 5A). Five chaetae Vi ventrally on head (Vi5 absent).
Tergite chaetotaxy as in Table 2B and Figs 4A and 6. Chaeta Di present on Th. I. Tubercles De and DL fused on Abd. IV. Tubercle L of Abd. IV slightly shift ahead the tubercle line Di-De-DL. Tubercles De and DL fused on Abd. V, separated from Di. Tubercle Di of Abd. V with Di1 macrochaeta, Di2 microchaeta and Di3 absent. Abd. VI not or hardly bilobed, with 1+1 areas of slightly enlarged and irregularly arranged secondary granules. S-chaetotaxic formula: 2+ms, 2/11111. No modified chaetae in male (Figs 4E, 5E).
Microchaetae of furcal rest minute and thick, smaller than secondary granules (Fig. 4D). Leg chaetotaxy given in Table 2C, similar to that of Ectonura monochaeta sp. n. (Fig. 2C). Tita without chaeta M and with chaetae B4-B5 short, not longer than other long chaetae of Tita. Claw untoothed, not striated in its basal part, and devoid of secondary granulation.
Derivatio nominis
This species is named in honour of Jean-Auguste Barra, for his important contribution to the knowledge of South African Collembola.
Ecology
This species was collected in the yellowwood forest leaf litter of Grootvadersbosch Nature Reserve. This is a remnant forest of the larger Tsitsikamma Forest Reserve situated 300 km to the south. The forest consists of indigenous trees such as yellowwood, ironwood and stinkwood.
Discussion
Ectonura barrai sp. n. is similar to Ectonura natalensis in its relatively complete chaetotaxy, but different in several details of chaetal arrangement. Based on the redescription of Coates (1968)[1], Ectonura natalensis has a more reduced chaetotaxy than Ectonura barrai sp. n.: absence of meso/microchaetae D, Di2 and De2 on head, absence of De2 on Th. I, absence of De3 and DL3 on Th. II-III, absence of Di2 on Abd IV-V. Conversely, chaetae Di2, De2 and DL2 on Abd. I-III of Ectonura natalensis are much larger than homologous chaetae of Ectonura barrai sp. n. (macrochaetae or large mesochaetae versus short mesochaetae). Chaetal groups De and DL of Abd. IV are separate in Ectonura natalensis versus fused in Ectonura barrai sp. n., and chaetal groups Di of Abd. V are fused on axis in Ectonura natalensis versus separate in Ectonura barrai sp. n. The unusual arrangement of S-chaetae on Ant. IV figured by Coates (1968)[1] is probably an erroneous interpretation, and not considered here as a valid differential character.
| A-Cephalic chaetotaxy | |||||
| Group of chaetae | Tubercle | Number of chaetae | Type of chaetae | Chaetae | |
| CL | (-) | 2 | M | F | |
| 2 | me | G | |||
| 1/2Af+Oc | (+) | 4 | M | A, B, Ocm, Ocp | |
| 2 | me | D, Oca | |||
| Di, De | (+) | 2 | M | Di1, De1 | |
| 2 | mi | Di2, De2 | |||
| DL | (+) | 2 | M | DL1, DL5 | |
| 2 | me | DL3, DL4 | |||
| 1 | mi | DL2 | |||
| L, So | (-) | 3 | M | L1, L4, So1 | |
| 5 | me | L2, So3 to 6 | |||
| B-Tergite chaetotaxy | |||||
| Di | De | DL | L | ||
| Th. I | 1 | 2 | 1 | - | |
| Th. II | 2-3 | 3+S | 3+S+ms | 3 | |
| Th. III | 2-3 | 3+S | 3+S | 3 | |
| Abd. I | 2 | 2+S | 2 | 3 | |
| Abd. II | 2 | 2+S | 2 | 3 | |
| Abd. III | 2 | 2+S | 2 | 3-4 | |
| Abd. IV | 2 | 4+S | 6 | ||
| Abd. V | 2 | 4+S | 3 | ||
| Abd. VI | 7 | ||||
| C-Leg chaetotaxy | |||||
| Scx2 | Cx | Tr | Fe | Tita | |
| Leg I | 0 | 3 | 6 | 13 | 18 |
| Leg II | 2 | 7 | 6 | 12 | 18 |
| Leg III | 2 | 8 | 6 | 11 | 17 |
| D-Sternite chaetotaxy | |||||
| Abd. I | VT: 4 | ||||
| Abd. II | Ve: 4 | (Ve1 present) | |||
| Abd. III | Ve: 3 | Fu: 4me+4mi | |||
| Abd. IV | Ve: 7 | VL: 4 | |||
| Abd. V | Ag: 3 | VL: 1, with L | |||
| Abd. VI | Ve: 12-13 | An: 2 mi* |
Original Description
- Janion, C; Bedos, A; Deharveng, L; 2011: The genus Ectonura Cassagnau, 1980in South Africa (Collembola, Neanuridae, Neanurinae), with a key to South African Neanurinae ZooKeys, 136: 31-45. doi
Other References
- ↑ 1.0 1.1 Coates T (1968) The Collembola from South Africa – I : The Genus Neanura. The Journal of the Entomological Society of southern Africa 31: 185-195.
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