Bromodesmus riparius, Mesibov, Robert, 2004

Mesibov, Robert, 2004, A new genus and four new species of millipedes from Tasmania, Australia (Diplopoda: Polydesmida: Dalodesmidae), with notes on male leg setae in some Tasmanian dalodesmids, Zootaxa 558, pp. 1-19 : 11-12

Bromodesmus riparius n. sp.

Figs. 2 , 3 , 8 ; map Fig. 10

Holotype: Whisky Creek, DQ213426 (41°09’50”S, 146°03’43”E), 100m, 27.iv.2004, R. Mesibov, QVM 23:45811.

Paratypes: 3 males, same details as holotype, AM KS88218; male, same details, QVM 23:45803, in absolute ethanol; 16 males, same details, QVM 23:45812, 2 dissected; 16 females, same details, QVM 23:45813.

Other material examined: 2 males, 6 females and 11 juveniles; see Appendix for details.

Diagnosis: Telopodite with flattened, distal projection posteriorly, basal to “hood”.

Description: As for genus. Length ca. 12 mm, maximum vertical diameter ca. 1.0 mm. In alcohol, well­colored specimens with head light brown on vertex, darker brown below; prozonites and metazonites light brown and translucent, revealing irregular subcuticular patches of light­colored material which may be fat deposits; metazonites with dark brown posterior margin, giving the animal a coarsely mottled appearance with narrow annular banding; cuticle sometimes clear just anterior to ozopores on pore­bearing segments, allowing view of dark­colored gut contents and giving appearance of large, dark lateral spots; legs and antennae light brown basally, dark brown distally.

Paranotum on segment 2 indicated only by slight marginal thickening. Subsequent segments with very slight lateral swelling bearing narrow, shallow, longitudinal groove on segments 3–11 (sometimes to segment 12, 13 or 14); on more posterior segments, no groove and almost no detectable swelling.

Telopodite ( Fig. 8 ) as in B. catrionae but with solenomerite arising at about one­quarter the telopodite length, laterally flattened, curving slightly posteriorly, then abruptly anteriorly, then posteriorly; tapering slightly, then tapering more strongly near posterodistally (sometimes distally) directed tip. From solenomerite origin, telopodite narrowing and flattening anteroposteriorly, with short, broad, flattened, distal projection on side closest to solenomerite; at about three­quarters its length, telopodite flattening further and greatly expanding into posteriorly concave ‘hood’ fringed with long, straight teeth laterally and distally; anterior surface of ‘hood’ with a few small, laterally flattened projections.

Distribution and habitat: So far known only from nine low­elevation sites in wet eucalypt forest in two areas in northwest Tasmania ca. 40 km apart ( Fig. 10 ). At the type locality it seems to be restricted to deeply shaded, richly organic soil close to very small streams.

Etymology: Latin riparius , of stream banks, adjective.

Figures

FIGURE 2. Bromodesmus spp. females. (A) B. catrionae n. sp. (QVM 23: 22082), (B) B. militaris n. sp. (QVM 23: 15150), (C) B. riparius n. sp. (QVM 23: 45813) and (D) B. rufus n. sp. (QVM 23: 40519). Scale bar = 10 mm.

FIGURE 3. Bromodesmus riparius n. sp. Right lateral views of males with gonocoxae retracted into aperture (left) and extruded (right). Both specimens from type locality (QVM 23: 45812).

FIGURE 8. Bromodesmus riparius n. sp. (Left) SEM view of left gonopod in situ (QVM 23: 45812). Note that the shapes of the ‘ hood’ and the solenomerite tip have been somewhat distorted in preparing the specimen for electron microscopy. Scale bar = 0.25 mm. (Right) Lateral view of distal portion of left telopodite (QVM 23: 40529). Dashed line shows course of prostatic groove; for clarity the continuation of the groove to the tip of the solenomerite is not indicated.

FIGURE 10. Known localities in Tasmania of Bromodesmus catrionae n. sp. (triangles), B. militaris n. sp. (squares), B. riparius n. sp. (round dots) and B. rufus n. sp. (crosses).