Aristocypha fenestrella
Creators: name: Orr, Albert G. W.
name: Dow, Rory A.
name: Steinhoff, Philip O. M.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Odonata
Chlorocyphidae
Aristocypha
Aristocypha fenestrella

description: Aristocypha fenestrella (Rambur)
(Figs 4b, 5b, 6c, 7b, 8b, 9b, 12f, 14a, b, 15a, b, 17a, 18a)
Material examined. MALAYSIA, 1 ♀ F (RMNH. INS.500054), Tributary of Sungai Telom, Cameron Highlands, Pahang, 4.613N, 101.404E, 19 ix 2008, leg. C.Y. Choong.
Habitus: very similar to H. biseriata with the following differences: overall slightly larger with long, thin banded legs relatively slightly shorter (Fig. 4b); very similar mottled pattern on the body darker in specimen examined (not figured); sagittate head, antennae and very similar to H. biseriata; abdomen obviously narrower and more elongate, bearing distinct lateral keels on most segments; caudal spikes relatively shorter and less tapered than in all other species studied, with numerous short rearward pointing spines and setae.
Head: in dorsal view as illustrated (Fig. 5b), almost identical to H. biseriata except antennae relatively slightly shorter (1.44 times maximum head width versus 1.52 in H. biseriata) and markings stronger and with slight differences but tip of pedicel with similar dark coloration; scape of similar length but with longer and mainly straighter setae so that even wet specimens appear smooth, rather than warty (Fig. 6c). Labrum as in H. biseriata except ‘moustache’ with 14 setae. Ventrally, genae bear a cluster of subocular spines longer and less numerous than in H. biseriata, with anterior strong three distinctive, being longer, more curved and sharply acuminate; remaining spines differ as shown (Fig. 7b). Proportions and other features of head seen in lateral view very similar to H. biseriata with small differences as shown (Fig. 7a, b), some of which may relate to subtle differences in angle of view, although ventral spur at margin of gena and occiput is clearly directed forward more strongly and the post occipital dorsal tubercle set further back in A. fenestrella. Mask long and thin, articulation resting between anterior part of coxae of mesothorax (Fig. 8b) as in H. biseriata; prementum narrow basally, gradually flared anteriorly with margins of anterior half weakly convex, slightly more so than in H. biseriata; similarly lateral margins with sparse fine setae on distal 2/3 rd (Fig. 9b) seated in slightly raised sockets (Fig. 11a); anterior median lobe as in H. biseriata but slightly more produced; median cleft almost completely closed with tinted groove marking line of closure (Fig. 11a); lobe of labial palp bifid with shorter process on each branch as in H. biseriata with slight differences in degree of torsion of distal lobe and form of processes as indicated (Figs 8a, 10a, b, c); movable hook long and strongly curved inward. Maxillae general form and arrangement of setae as in H. biseriata; apical tooth with row of three inner denticles (Fig. 12f), all well separated, longest one apicad, all finer and longer than in H. biseriata. Mandibles (Figs 14a, b, 15a, b)—both left and right with five distinct teeth on incisor visible in internal view; right with small supplementary tooth basal to strong ventral tooth; right molar crest a low swelling with two strong, sharp spines, the ventral being longer, heavily sclerotised (Fig. 14a, 15b); left incisor (Figs 14b, 15a) with five well developed teeth, the strongest ventrally; molar crest a strong flat dorso-ventral blade with 13 minute denticles along a convex distal margin, with end denticles markedly heavier and longer, especially ventrally (Figs 14b, 15a). Strong basal seta on both mandibles as in H. biseriata (not visible in Fig. 14a).
Thorax: prothorax saddle-shaped with anterior and posterior flanges and tubercles as in H. biseriata (Fig. 5b). Marking (not illustrated on body) pale and mottled but always with broad pale band pale between two anterior tubercles on prothorax. Wing sheaths slightly spatulate, not completely obscuring abdomen at sides, forewing reaching to end of S4, hindwing to 2/3 along S5 (Fig. 4b). Legs long and thin, metafemur reaching midpoint of S6, clearly shorter than in H. biseriata which they resemble in all other respects including the presence of two rows of pectinate setae on the underside of the tarsus.
Abdomen: squat, mainly dark with well-defined pale narrow middorsal stripe (not figured). Margins of S2–8 distinctly crimped forming shallow lateral keels; dorsal surface similar to H. biseriata with sparser setae; ventrolateral margin of S9 with ca 4 strong, curved spines intermingled with 4–5 smaller spines and scattering of tiny marginal and submarginal spines along venter; S10 hind-margin with 4 strong rearward pointing ventrolateral spines (Fig.17a). Male gonapophyses (Fig. 17a) short and conical, well separated, arising near posterior margin S9 and just reaching margin hind margin. Female gonapophyses unknown. Epiproct, short, subconical, not obviously different from H. biseriata. Caudal spikes about 40% body length, broad for most of their length and tapered abruptly to a point subapically (Fig. 18b); bearing numerous backward facing strong sharp spines on outer margin, these rather sparse on inner margin; heavy setae, and also long fine setae too entangled to assess accurately, but appear to be less profuse than in H. biseriata.
Measurements (in mm): body length excluding antennae, caudal appendages and spikes 12.4; lateral caudal gills 5.3; head width 2.81; prementum 2.45; palpal lobe (to tip of dorsal branch) 0.80; movable hook 0.68; maxillae base to distal hook of galeolacinea (1.26), maxillary palp (0.55); mandibles long axis (0.86); antenna 1.70, 0.65, 0.70, 0.50, 0.29, 0.16, 0.07 (total 4.07).
Remarks
The principal diagnostic differences between A. fenestrella and H. biseriata are the longer subocular anterior spines on the genae and the relatively shorter caudal spikes, tapering to a point abruptly near apex in the former. The length of the spikes in proportion to body length is ca 40% in A. fenestrella versus ca 55% in H. biseriata. The legs in A. fenestrella are proportionally shorter. There are also clear differences in the armature of the maxillae and dentition of the mandibles and the setae on the scape of the antenna are mainly long and do not create a warty appearance when wet. The larvae of two other species of Aristocypha have been described in some detail. Aristocypha trifasciata and A. quadrimaculata by Kumar & Prasad (1977). Both species differ from Heliocypha in possessing long setae on the scape without a warty appearance and the caudal spikes are proportionally shorter (ca 40% body length), and are not tapered until near the apex, as in A. fenestrella. In other respects consistent genus specific characters are not evident. For example in A. trifasciata the subocular spines on the genae are small and scattered, whereas in A. quadrimaculata they are very similar to those found in A. fenestrella. Conversely, in A. trifasciata, the legs are relatively shorter than in A. fenestrella, whereas in A. quadrimaculata they are much longer. In both species the prementum, while of similar general shape to A. fenestrella, is much wider anteriorly and the median cleft is well defined. Hence only the terminal shape of the caudal spikes consistently separates Heliocypha and Aristocypha based on known larvae.
description: Published as part of Orr, Albert G. W., Dow, Rory A. & Steinhoff, Philip O. M., 2024, Descriptions of larvae of four mainly DNA barcode-matched species of chlorocyphids from south-east Asia (Odonata: Chlorocyphidae) with notes on the generic and species level larval identification of Oriental region members of the family., pp. 301-337 in Zootaxa 5486 (3) on pages 315-316, DOI: 10.11646/zootaxa.5486.3.1, http://zenodo.org/record/13210005