Enderleina khazeni, Derka, Tomáš & Figueroa, J. Manuel Tierno De, 2013

Derka, Tomáš & Figueroa, J. Manuel Tierno De, 2013, Enderleina khazeni n. sp. (Plecoptera, Perlidae), a new stonefly from Venezuelan Guayana, Zootaxa 3619 (1), pp. 75-78 : 76

Enderleina khazeni n. sp. Derka & Tierno de Figueroa

Figs. 1 a–d.

Type material. Holotype: Venezuela, Bolívar Province, Gran Sabana, Río Tarota, below the road to Santa Elena de Uairén, 1,320 m a.s.l., 5º 48’ 57’’ N, 61º 25’ 8’’ W, 19-XI-2011, 1 male, Derka leg. Paratype: Venezuela, Bolívar Province, Gran Sabana, Río Torón, above Salto Toroncito, 1,384 m a. s. l., 5º 43’ 37’’ N, 61º 36’ 35’’ W, 20-XI-2011, 1 male, Semelbauer leg.

The holotype and paratype are deposited in the Collection of the Musée Cantonal de Zoologie (Lausanne, Switzerland) with the registration numbers, 69029 for the holotype and 69030 for the paratype.

Type locality. Río Tarota, Bolívar Province, Venezuela.

Etymology. The species is named after Frank Khazen, a great person, Gran Sabana expert and friend of TD, who unexpectedly passed away in March 2012.

Description. Male holotype ( Fig. 1 a–d): Total length: 12 mm, Forewing: 12.6 mm. General colour brownish black except the prothorax (both dorsally and ventrally) that is orange in the living specimen and yellow once preserved ( Fig. 1 a). Antennae black, lighter proximally. Three ocelli, the anterior one smaller. Mouth parts light brown. Wings infuscated with brown. Legs, abdomen and cerci black. Cerci with long and abundant setae. Abdomen hairy ( Fig. 1 b–c). Sternum IX wider than long (1.25 wide/long) with long dark bristles and a pale, rounded and flattened hammer (0.15 mm diameter) ( Fig. 1 c). Hammer set on a dark band with two elongated, adjacent, pale areas. Paraproct laterally pointed. Aedeagus with a median, triangular shaped sclerite and a pair of long, slender basolateral spines ( Fig. 1 d). Each spine bearing ventrally an enlarged, subapical fan-shaped structure which terminates in a blade-like structure extending to midlength of the median sclerite. Aedeagus with numerous spine-like setae.

The male paratype differs from the holotype slightly in size (total length: 9.3 mm, forewing: 12.4 mm) and coloration (mouth parts and ventral part of the head pale brown-orange, and body slightly paler ventrally than the holotype).

Affinities: The male of E. khazeni can be clearly distinguished from the males of E. preclara , E. yano and E. froehlichi mainly by the shape of the penial sclerites and of the paraprocts ( Jewett 1960; Stark 1989; Ribeiro-Ferreira & Rafael 2005). The spines are narrowed in the apical third of the penial sclerites in E. preclara , whereas in E. yano they are more gradually tapered, in E. froehlichi they are considerably stronger, and in E. khazeni they have a characteristic shape ventrally extending as an enlarged fan-shaped structure, dorsally terminating in a blade-shaped structure. Moreover, dorsally the spines in E. khazeni reach near the apex of the median sclerite, whereas in E. preclara and E. froehlichi these structures are considerably shorter. The paraprocts are laterally pointed in E. khazeni , not slightly notched at the tip as in E. yano , they lack a subapical denticle as in E. froehlichi , and they are not bulbous at the apex as in E. preclara . Enderleina khazeni can be also distinguished from E. yano and E. froehlichi by their coloration: E. yano has a narrow orange V-mark connecting the antennal bases and anterior ocellus, and the basal half of the femora are yellow (according to Stark 1989), and E. froehlichi has a pale brown body. Enderleina preclara is similar to E. khazeni in colour, but the latter has two large pale areas laterally on sternum IX, not mentioned or illustrated by Jewett (1960) in the description of E. preclara . Despite the previous list of differences, E. khazeni seems to be more closely related to E. preclara , and it is the species found in closest proximity.

Ecological notes. The holotype was captured by light trapping. The type locality is ca. 10 m wide and up to 1 m deep with riffles and small cascades. The substrate consists primarily of boulders (megalithal) and stones (macro- and mesolithal) and some aquatic macrophytes. Water temperature was 21 °C, pH = 5.89. The paratype was captured netting on the bank of a medium sized river with stony substrate (mega- and mesolithal), water temperature 20.1°C, pH = 5.6. Both rivers are surrounded by savannas and remnants of riparian forests.

Figures

FIGURE 1. Enderleina khazeni n. sp. Male; a) habitus of a preserved individual; b) terminalia, dorsal; c) terminalia, ventral (slightly oblique), showing the IX sternum; d) penial armature and basal part of the aedeagus (tubular membranous part not shown).