Helobdella buzz, Iwama, Rafael Eiji, Nogueira, João Miguel De Matos & Gonçalves, Ana Zangirolame, 2017

Iwama, Rafael Eiji, Nogueira, João Miguel De Matos & Gonçalves, Ana Zangirolame, 2017, Helobdella buzz n. sp. (Clitellata: Hirudinida), a bromeliad leech from the Brazilian Atlantic Forest, Zootaxa 4272 (4), pp. 591-595 : 591-593

Helobdella buzz n. sp.

Type series. Holotype ( MZUSP 237 ): coll. Ilha do Cardoso, state of São Paulo, Brazil, 16.XII.2011, in Vriesea procera . Paratypes ( MZUSP 238–247 ): Ilha do Cardoso , state of São Paulo, Brazil, 16.XII.2011, 49 specimens, in Vriesea procesa and Quesnelia arvensis ; paratypes ( MZUSP 248–250 and ZUEC-CLI 024–025): Estação Ecológica Juréia-Itatins , state of São Paulo, Brazil, 14.XII.2013, 17 specimens, in Vriesea procera .

Diagnosis. One pair of comma-shaped eyespots well separated from each other; nuchal scute and nuchal gland both absent; protrusion of the skin from VII a1 to VIII a2; papillae, sensillae and lines on the dorsal surface all absent; gonopores separated by one primary annulus; mid-body somites triannulated, ([a1]+[a2]+[a3]); one pair of salivary glands, compact; six pairs of gastric caeca, last pair forming post-caeca; ascendant portion of the ejaculatory ducts from XIII/XIV to XI/XII; six pairs of testisacs.

Description. Body shape. 2–7 mm in length; maximum width ± 2 mm; body sublanceolate ( Fig. 1 A and 1B), dorsoventrally flattened; anterior sucker well-developed, somewhat triangular ( Fig. 1 C); margin of annuli rounded, raised from body wall; head region somewhat triangular; posterior sucker ± 0.5 mm, ventral.

External morphology. Body pale to uniformly brownish, lacking metameric patterns of pigmentation and also longitudinal lines on both ventral or dorsal surfaces ( Fig. 1 A–F); papillae and sensillae both absent; one pair of commashaped eyespots at 4/5, well separated from each other ( Fig. 1 D); nuchal scute absent; nuchal gland absent; protrusion of skin formed by muscular fibers from VII a1 to VIII a2 ( Figs 1 F and 2A); male gonopore at XII a1/a2, female gonopore at XII a2/a3, separated by one primary annulus ( Fig. 1 E and 2C); two post-anal annuli; somites I-V: total of seven annuli; somite VI: ([a1+a2]+[a3]), sometimes ([a1]+[a2]+[a3]); somites VII-XXIV: triannulate, somite formula ([a1]+[a2]+[a3]); somite XXV: biannulate; somites XXVI and XXVII: uniannulate.

Internal morphology ( Fig. 3 ). Base of pharynx in XIV; compact saliary glands in XIII ( Fig. 2 B and 2D); Linear salivary ducts in XII/XIII, at base of proboscis; six pairs of gastric caeca not inclined anteriorwards, last pair forming post-caeca; four pairs of intestinal caeca inclined anteriorwards; male atrium located anteriorly to ganglia XII; ejaculatory ducts with wide preatrial loop, ascendant part from XIII/XIV to XI/XII, forming loop of variable shape lateralwards in XII; six pairs of testisacs, first pair in XIII/XIV, last pair in XVIII/XIX; ovisacs tubular in XII, descending to XIV.

Remarks. The most remarkable external character of Helobdella buzz n. sp. is the protrusion of the skin from VII a1 to VIII a2. Two other species of leeches share the presence of similar protrusion, H. diploides Ringuelet, 1948 and H. nununununojensis Siddall, 2001a . Among leeches belonging to H. diploides , however, the protrusion of the skin comprises a single primary annulus (VIII b1/b2) ( Iwama & Arruda 2016; Ringuelet 1948, 1985). In addition, the internal morphology of H. diploides is quite different, as the salivary glands are diffuse among members of that species, while among individuals belonging to H. buzz n. sp. there is one pair of compact salivary glands.

Members of H. nununununojensis Siddall, 2001b also possess a protrusion of the skin on the nuchal region and compact salivary glands, however, the protrusion of the skin is shorter in animals belonging to that species, restricted to VIII a1, and they have longer ejaculatory ducts, extending to XIX ( Siddall 2001a), while in leeches belonging to H. buzz n. sp., the ejaculatory ducts do not extend beyond XIII/XIV.

Members of two other species belonging to this genus share with specimens of H. buzz n. sp. the presence of compact salivary glands, H. sorojchi Siddall 2001b and H. bolivianita 2001a , but members of the former species are easily differentiated from H. buzz n. sp. by having weak subdivisions of the primary annuli from VIII through XV ( Siddall 2001b), while members of H. bolivianita have both diffuse and compact salivary glands, and also a nuchal scute at VIII ( Siddall 2001a), which is absent in leeches belonging to H. buzz n. sp.

Etymology. The species is named after the Pixar’s character Buzz Lightyear, a toy space ranger hero of the Toy Story blockbuster. The epithet “ buzz ” is used here in apposition according to the article 34.2.1 of the International Code of Zoological Nomenclature (ICZN 1999). The protrusion of the skin on the nuchal region of Helobdella buzz n. sp. is a main diagnostic characteristic and its size and location resemble an astronaut helmet, as that of Buzz Lightyear.

Figures

FIGURE 1. External morphology of Helobdella buzz. A. Entire leech, dorsal view showing the protrusion of the skin (arrow); B. Entire leech, ventral view; C. Ventral view of the anterior end; D. Dorsal view of the anterior end showing the eyespots (arrows); E. Ventral view of the genital region showing male (M) and female (F) gonopores; F. Lateral view of the anterior end showing the protrusion of the skin (arrow).

FIGURE 2. Longitudinal sections of Helobdella buzz. A. Nuchal region showing the internal structure of the protrusion of the skin; B. Segments XII-XIV showing the position of the compact salivary glands (arrow). C. Male (yellow arrow) and female (red arrow) gonopores. D. Genital region showing the compact salivary gland (arrow).

FIGURE 3. Internal morphology of Helobdella buzz. A. atrium; ED. ejaculatory duct; G. ganglium; GC. gastric caecum; O. ovisac; P. proboscis; PC. post-caecum; SD. salivary duct; SG. salivary gland; T. testisac.