Siphonophora hebetunguis ( Attems, 1951 )

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 : 3-8

publication ID

https://doi.org/ 10.5852/ejt.2019.496

publication LSID

lsid:zoobank.org:pub:B14B79E2-8C70-483B-B38B-7B780C3F1192

DOI

https://doi.org/10.5281/zenodo.5690130

persistent identifier

https://treatment.plazi.org/id/03F14B21-9C06-DE15-4556-1129FE0E35AB

treatment provided by

Plazi

scientific name

Siphonophora hebetunguis ( Attems, 1951 )
status

 

Siphonophora hebetunguis ( Attems, 1951) View in CoL

Figs 1–2 View Fig. 1 View Fig. 2 , 9A View Fig. 9

Rhinosiphora hebetunguis Attems, 1951: 228 View in CoL .

Siphonophora hebetunguis View in CoL – Jeekel 2001: 59.

Diagnosis

Small, pale species with paddle-shaped claws, generally very tuberculate on head, collum, metazonites and coxae. Ventral margin of pleurites almost straight, hind margin with some tubercles. Accessory claw short and arising from lateral side of the claw. Anterior gonopods short and squat, with no spines or other structures at the tip.

Etymology

A noun in apposition from the Latin ‘ hebe ’, meaning ‘blunt’ or ‘dull’ and ‘ unguis ’, meaning ‘claw’ and referring to the shape of the claw. Note that in the original description the spelling hebetungis appears, although the key and figure legends use the spelling hebetunguis . The type series from Vienna is labelled hebetungis. As ‘ unguis ’ means ‘claw’ and the claw shape is referred to in the description, it appears that the use of ‘ hebetungis ’ is probably a lapsus calami and that the spelling hebetunguis can be taken as correct.

Material examined

None of the material is labelled as types, and all the specimens should be considered as syntypes. Two microscope slides, containing the head, first seven body rings, telson, and anterior and posterior gonopods, in combination with a separate body in fluid, constitute a potential lectotype, but we refrain from formally designating it as such. The original description does not list the number of specimens, although both males and females were obviously present.

BRAZIL • 6 ♂♂, 2 ♀♀; ‘Brasilien, Taperinha près Santarem. Coll Zerny’; NHMW 2295 View Materials .

Redescription

Mostly made from the non-mounted specimens, as the slides are so cleared that most structures are not easily visible.

MEASUREMENTS. Body length: ♂: 5.2–11.25 mm, ♀: 15–17 mm. Body width: ♂: 0.54–0.64 mm, ♀: 0.88 mm. Number of podous tergites: ♂: 33–50, ♀: 57–62. Number of apodous tergites: ♂: 0, ♀: 1–2.

COLOUR. Pale cream (but may be due to state of preservation).

BODY SHAPE. More or less parallel-sided.

HEAD. In dorsal view showing sinuous or stepped outline laterally between antennal bases and base of rostrum. In lateral view almost flat, with slight demarcation between rostrum and rest of head. Rostrum very slightly downwardly curved. Length of rostrum (to antennal base): ♂: 0.34–0.56 mm, ♀: 0.42– 0.56 mm. Width of head (between antennal sockets): ♂: 0.20 mm, ♀: 0.24–0.26 mm. Abundant setae and tubercles on head. Long setae on gnathochilarium at base of rostrum, some of which reach to rostrum tip.

ANTENNAE. Appearing more or less the same length as rostrum but exact length not analysed, nor length:width ratio of segments. Sensory pits on antennomeres 5 and 6 present but not especially clear or large.

COLLUM. Wide, anterior margin with a gentle curve for anterior margin (not examined in SEM). Posterior margin more or less straight. With abundant setae and tubercles.

TERGITE 2. More than 0.5 × length of collum.

MID- BODY RINGS. When plotted ( Fig. 1 View Fig. 1 ) this species has a small body size and relatively few rings in the males, but there are not enough females to give a clear picture. Paranota not obvious. Slightly castellated, especially anteriorly. Relative width of pro- and metazonites 0.83–0.95. Prozonites with tubercles, but no setae, metazonites with abundant setae, none long, and tubercles. Prozonite with a channel-like area just in front of the border with the metazonite. Limbus very clearly crenulated under SEM. Ventral margin of pleurites almost straight, although with slightly bilobed margin in anterior few rings. Hind edge of pleurite from inside with clear but irregular tubercles, not serrate but with some setae. Ozopores very difficult to see. The original description does not report on which ring they start, but they were said to be on small protuberances; this may well be due to the state of preservation. In specimens viewed here, the protuberances were not obvious.

LEGS. Length relative to body height and length:width ratio of podomeres not analysed. Coxae tuberculate. Claw broadly expanded and paddle-shaped on anteriormost legs of males and females; by approximately leg pair 80 becoming more conventionally claw-shaped. Accessory claw: short, ¼–½ length of claw, quite broad and with rounded tip, arising from lateral side of claw.

TELSON. Length:width ratio 0.42–0.6.

ANTERIOR MALE LEGS (pairs 1–8). Appear normal.

ANTERIOR GONOPODS ( Fig. 2D View Fig. 2 ). Short and squat, with segments evidently fused together so exact number is difficult to see. Pair of gonopods appearing like two cupped hands with the cup facing ventrad. Ventral surface with setae but lateral surface without. No apparent enlarged setae or other structures at tip of anterior gonopods, including in slide-mounted syntype (note that in those illustrated in Fig. 2D View Fig. 2 tip of a posterior gonopod protrudes, looking like a structure at tip of anterior gonopods).

POSTERIOR GONOPODS. Not visible in situ in any specimens but original illustrations showed it to be of ‘typical’ siphonophorid type with last segment long, thin, with spine towards base and a simple doublepointed tip. Slide mount shows spine, although tip is not clear.

Remarks

All specimens were found at the same time of the year at the same location. The original description of R. hebetunguis describes ozopores situated on slight protuberances. However, in all the species described here (and in species of Columbianum as well, Read & Enghoff 2018) the ozopores are surrounded by a ring of setae. As noted earlier, this can sometimes give the appearance of the ozopores protruding. Examination of various species in the Natural History Museum in London revealed some with clear paranota, for example S. longirostris Silvestri, 1895 , unlike in any of those in the current collection. See Table 1 View Table 1 for a comparison of the features of S. hebetunguis and the other species of Siphonophora from Brazil, as well as S. portoricensis Brandt, 1837 .

The new species described below differ from S. hebetunguis in the structure of the anterior gonopods as well as in some other somatic characters. They do, however, have claws that are shaped similar to those described for hebetunguis .

Table 1. Distinguishing features of species of Siphonophora Brandt, 1837 from Brazil.

  hebetunguis pubescens setaepromissa tuberculata portoricensis
Details taken from type material literature fresh material fresh material literature
Overall size up to 17 mm up to 10 mm up to 19 mm up to 10 mm holotype 17 mm
No. body rings 33–50 29–62 28–82 16–45 51–79
Head shape (dorsal view) sinuous lateral margin triangular sinuous lateral margin roughly triangular more triangular
Mandible tip unknown unknown sponge-like pointed unknown
Tubercles on head and collum abundant none mentioned some abundant none mentioned
Caudal margin of collum more or less straight illustration ambiguous, perhaps slight anterior curve? more or less straight slightly curved caudally shallow anterior curve
Tergite 2 > 0.5 length of collum > 0.5 length of collum approx. 0.5 length of collum less than 0.5 length of collum unknown
Claw shape blunt & spoon-like normal (probably) blunt and spoon-like broader than simple claw but not spoon-like ‘uncinate’ simple, perhaps broad
Accessory claw short, to ½ length of claw small short, to less than ½ length of claw short, to ½ length of claw apparently absent
Limbus crenulate unknown not crenulate not crenulate unknown
Coxae tuberculate smooth smooth tuberculate unknown, appear smooth in illustration
Channel between pro- and metazonites no setae visible in SEM unknown single line of setae and some tubercles single line of setae, no tubercles unknown
Tubercles on prozonites present unknown absent present unknown
Pleurites ventral margin slightly bilobed in anterior, rest more or less straight sinuous clearly bilobed slightly bilobed in anterior, rest more or less straight unknown
Relative length of pro-/ metazonites 0.83–0.95/1 unknown 0.82–0.95/1 0.66–0.92/1 unknown
Setal length short short may be very long in some males short described as variable
Anterior gonopods blunt-tipped; median lobe perhaps present; some setae near the tips two subequal parts, large, each with rounded tips, one slightly hooked; no special structure near the tips; median lobe apparently missing uneven ‘S’ shape; apex narrow, blunt and spoon-shaped; 1 large seta on mesal side on separate basis; several wide, ribbon-like setae near tip; median lobe present large claw at tip 1 wide; ribbon-like seta on lateral side; median lobe may or may not be present with a waist, apex rounded, lobe on medial side, no special structures at tip
Posterior gonopods strongly tapering; spine near base; double-pointed tip strongly tapering; no apparent spine near base; small claw-like tip strongly tapering; large accessory spine near base; blunt tip more parallel-sided; small spine near base; tip perhaps forked strongly tapering, no obvious spine, slightly pointed tip

Kingdom

Animalia

Phylum

Arthropoda

Class

Diplopoda

Order

Siphonophorida

Family

Siphonophoridae

Genus

Siphonophora

Loc

Siphonophora hebetunguis ( Attems, 1951 )

Read, Helen J. & Enghoff, Henrik 2019
2019
Loc

Siphonophora hebetunguis

Jeekel C. A. W. 2001: 59
2001
Loc

Rhinosiphora hebetunguis

Attems C. 1951: 228
1951
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