Siphonophora tuberculata, Read & Enghoff, 2019

Read, Helen J. & Enghoff, Henrik, 2019, Siphonophoridae from Brazilian Amazonia. Part 2 - Two new treeclimbing species of the genus Siphonophora, including one showing pilosity polymorphism (Diplopoda, Siphonophorida), European Journal of Taxonomy 496, pp. 1-26 : 15-17

Siphonophora tuberculata sp. nov. urn:lsid:zoobank.org:act:2DD9F3C7-6364-4F67-96A7-338B10A9A4DB

Figs 1 , 7 , 9C

Diagnosis

Small, pale species, with claws blunt and slightly expanded but not as clearly paddle-shaped as in S. setaepromissa sp. nov. or S. hebetunguis . Abundant tubercles on head, collum, pro- and metazonites and coxae. Pleurite ventral margin almost straight, hind margin crenulated. Accessory claw short, laterally located on the claw. Anterior gonopods with spines at the apex and a larger seta laterally.

Etymology

The specific name refers to the abundant tubercles on many parts of the body.

Material examined (total: 4 ♂♂, 7 ♀♀)

Holotype

BRAZIL • ♂; Amazonas Province, Rio Tarumã Mirím, Terra Firma; secondary, non-inundated forest; 03°02′ S, 60°17′ W; B49; 14 Mar. 1983; Adis and Rodrigues leg.; BTM; arboreal photoeclector B49

BTM BE↓; INPA. Paratypes

BRAZIL • 1 ♀; same collecting data as for holotype; TM K10; Kempson extractor; 23 Nov. 1983; INPA • 1 ♀; same collecting data as for preceding; TM K10 ; Kempson extractor; 23 Nov. 1983; NHML • 1 ♀; same collecting data as for preceding; TM K10 ; Kempson extractor; 23 Nov. 1983; NHMD • 1 ♀; same collecting data as for preceding; TM E10 ; ground photo-eclector; 11 Dec.1982; ZMUM • 1 ♂; same collecting data as for preceding; TM K24 ; 26 Oct. 1982; INPA • 1 ♂; same collecting data as BE for ↓; preceding; TM K16; 30 Jan . 1983; NHMD • 1 ♂; same collecting data as for BE↓; preceding; B49 BTM 14 Mar. 1982; INPA • 1 ♀; same collecting data as for preceding; 49 ATM BE↓; arboreal photo-eclector; 1 Feb.1982; INPA • 1 ♀; same collecting data as for preceding; 49ATM BE↓; arboreal photo-eclector; 21 Jan. 1982; INPA • 1 ♀; same collecting data as for preceding; B49 BTM 21 Jan. 1982; INPA .

Description

MEASUREMENTS. Body length: ♂: 6.75–8.8 mm, ♀: 2.47–10.85 mm. Body width: ♂: 0.48–0.58 mm, ♀: 0.3–0.8 mm. Number of podous tergites: ♂: 34–43, ♀: 16–45. Number of apodous tergites: ♂: 1, ♀: 1.

COLOUR. Most specimens are pure white, but this may be due to reservation. One female has slightly darker head and first few body rings.

BODY SHAPE. More or less parallel-sided, some appear slightly narrow at the mid-body.

HEAD. In dorsal view lateral edges of head appear to have ‘step’ between antennal bases and base of rostrum. In lateral view head gently and gradually sloping ventrally, almost flat, with no dome and no abrupt change between rostrum and rest of head. Rostrum more or less straight, flat and barely curving downwards. Several individuals with ‘mouths’ open and under SEM rostrum seems to consist of extension of head capsule above, gnathochilarium below and mandibles to sides. Mandible tip appears to be pointed and mandible itself grooved. Length of rostrum (to antennal base): ♂: 0.4–0.46 mm, ♀: 0.15–0.54 mm. Width of head (between antennal sockets): ♂: 0.2–0.26 mm, ♀: 0.12–0.24 mm. Abundant setae and tubercles across whole of head capsule. Several long setae on the gnathochilarium, not reaching tip of rostrum, small setae on sides of rostrum right up to tip.

ANTENNAE. Appear to be approximately as long as rostrum, certainly not great deal longer.

COLLUM. With abundant setae and tubercles, including lots of tubercles along the margin. Wide, with gentle curve to anterior margin and membranous V.

TERGITE 2. Less than 0.5 × length of collum.

MID- BODY RINGS. Females of S. tuberculata sp. nov. are separated from those of S. setaepromissa sp. nov. on the graph ( Fig. 1 ) by having fewer rings for their body width. This difference not obvious in males. No obvious paranota. Slightly castellated, perhaps slightly more marked anteriorly, but relatively evenly. Relative width of pro- and metazonites 0.66–0.92 (all but one, 0.8–0.92). Metazonites with abundant tubercles and setae. Prozonites with collapsed tubercles, more pronounced in structure than just cytoscutes, and with no setae. No examples of long setae in any males, of which there were only three. Channel between prozonites and metazonites with a line of setae, but no tubercles. Limbus with a slightly bumpy margin, but not regularly crenulated. Ventral margin of pleurites slightly bilobed on first anterior body rings but subsequently almost straight, with a clearly crenulated margin (under compound microscope) and some setae. Ozopores starting on tergite 5 and finishing on the penultimate tergite, not on protuberances.

LEGS. Length 0.62 of body width (♀). Length:width ratio of podomeres (prefemur to tarsus) 1.43, 1.15, 1.47, 1.38, 12.3, 3.67. Coxae with tubercles. Terminal claw slightly enlarged, at least in males, though not as broadly paddle-shaped as in S. setaepromissa sp. nov. Accessory claw short, ¼–½ length of claw and arising laterally from claw, broad at base.

TELSON. Length:width ratio 0.42–0.77.

FIRST PAIRS OF MALE LEGS. Appear normal.

ANTERIOR GONOPODS. Impossible to count segments due to apparent fusion. Overall shape slightly angular in lateral view. Mesal lobe may or may not be present (ambiguous in some SEM images, not visible in others). Some setae on basal segments on the posterior side, not possible to see clearly on anterior side. Tip hook-like, both in overall shape, which is strongly tapered, and at very apex, which is pointed, ending in a claw. Setae on last segment strong and broad-based, but not ribbon-like except for one closest to tip, which is on lateral side, is parallel-sided, slightly uneven in direction and not as large as that on mesal side of S. setaepromissa sp. nov., although still reaching to tip of anterior gonopods.

POSTERIOR GONOPODS. Probably with 7 segments including the coxae, with no apparent setae on basal segments. Overall shape more parallel-sided than in S. setaepromissa sp. nov. Apical segment with a single accessory seta, but perhaps slightly smaller than in S. setaepromissa sp. nov. At point of insertion of seta the segment narrows abruptly. In SEM illustrated here posterior gonopods are both broken, but a different SEM mount shows they are unevenly twisted, less like a taut streamer and more like one blowing in the wind. The posterior gonopods of this specimen may also be broken, possibly with a forked tip.

Ecology

This species was found at the same locality and habitat as Columbianum nahvalr Read & Enghoff, 2018 . Most of the specimens were from the soil and extracted using a Kempson apparatus between October and January. Three females and a male were caught in downward catching photo-eclectors in January, February and March. This is a non-inundated area, but clearly this species spends time in trees as well as in the soil.

Figures

Fig. 1. Relationship between body width (mm) against the total number of tergites with legs for new species of Siphonophora Brandt, 1837 and S. hebetunguis (Attems, 1951).

Fig. 7. Siphonophora tuberculata sp. nov., paratype.A. Head and anterior rings,body width approximately 0.5 mm. B. Holotype, head in lateral view. C. Holotype, mid-body pleurites in lateral view. D. Gonopods in situ. E. Head in ventro-lateral view with mandible visible. Scale bars: B–C = 200 µm; D–E = 100 µm.

Fig. 9. Claws and accessory claws in the three species of Siphonophora Brandt, 1837 studied here. A. Siphonophora hebetunguis (Attems, 1951). B. Siphonophora setaepromissa sp. nov. C. Siphonophora tuberculata sp. nov. Not to scale.