Atlantodesmus Hoffman 2000
Creators: name: Bouzan, Rodrigo Salvador
name: Pena-Barbosa, João Paulo P.
name: Brescovit, Antonio Domingos
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Polydesmida
Chelodesmidae
Atlantodesmus

description: Genus Atlantodesmus Hoffman, 2000
Atlantodesmus Hoffman, 2000: 101 –113. Type species: A. eimeri (Attems, 1898), by original designation. Iemanja Hoffman, 2000: 101 –113. Type species: I. teresa Hoffman, 2000. New synonymy.
Justification of synonymy: Hoffman (2000) described two genera, similar in body features and gonopod structures: Atlantodesmus and Iemanja. Despite the similarities, Hoffman (2000) distinguished both genera through two features: presence of a cingulum and folds in the posterior margin of the gonopod opening in Iemanja (see Hoffman, 2000, figs 2, 14).
Our examination of specimens of the genus Atlantodesmus revealed that all species have folds at the posterior edge of the gonopod aperture, as well as a discontinuity in the transition zone between the prefemoral region and the acropodite region, indicating the presence of a cingulum in ectal view in all species. Hence, there is no reason to separate the species into two distinct genera.
Diagnosis. Males of Atlantodesmus differ from other chelodesmid genera by the combination of the following characters: transition zone of the pre-femoral region to the acropodal region with a cingulum (Fig. 7 C, 10C); acropodite branching proximally, forming long, thin falciform solenomere and a large acropodite process with a broadened apical region and overreaching the tip of the solenomere.
Description. Body length between 40 mm (A. itapurensis) and 74 mm (A. teresa). Coloration (specimens preserved in alcohol) variable among species, ranging from black to light brown. Head: face with three rows of bristles (Fig. 1 A), shape of the Tömösváry organ suboval (Fig. 1 B). Antenna: distal antennomere with invaginations between the four apical sense cones and spiniform basiconic sensilla (Figs 1 C–E). Body rings: integument with small tubercles on the metazonite (A. eimeri), rough in A. pintoi and A. teresa, and smooth in A. itapurensis and A. pickeli, all of them without bristles. Collum: anterior border arched and posterior border ranging from straight to slightly curved (Figs 2 A–B). Segments with lateral projections (Figs 8 B, 11B, 15A, 18B) dorsal to the stigma. Stigma oval (Fig. 2 E). Sternite of fourth segment with two ventral projections in A. itapurensis and A. teresa (Figs 11 A; 18A). Ozopore situated on the posterior edge of paranota. Ozopore arrangement: 5, 7, 9, 10, 12, 13, 15–19; ozopores surrounded by peritremata (Figs 2 C–D). Paranota: prominent and long, wide and nearly horizontal, slightly elevated on sides, covering part of the legs, without bristles on the edges. Paranota form: anterior corners rounded, posterior edges acutely produced (Fig. 2 C). Legs: without modifications, with thin and slightly elongated bristles (Fig. 1 F). Telson: triangular (Fig. 2 F), with five pairs of macrobristles on the dorsal side and two pairs in the apical region.
Male characters: Gonopore: located on the coxae of the legs of the third segment, coxae rectangular, with an apical pore (Fig. 3 C). Gonopod aperture on seventh body ring: transversely oval, large; posterior edge with folds (Figs 7 E–F). Central support of gonopods are sclerotized (Fig. 7 E, arrow). Gonopods: Gonopod coxae width (Fig. 3 A): equivalent to about half the length of the telopodite, often with spiniform process (Fig. 3 B); coxae prominent in ectal view. Cannula (Fig. 3 A): hook-shaped. Spermatic (prostatic) groove (Fig. 3 A): runs along mesal side of the acropodite, does not change trajectory at the cingulum. Telopodite (Fig. 3 A): elongated and inclined, divided into two parts: the prefemoral region (Fig. 3 A) and the femoral region (Fig. 3 A). Prefemoral process (Fig. 3 A): long branch without projections, reaching almost tip of solenomere. Cingulum: delimiting the prefemoral region and femoral region (Fig 3 B); conspicuous in A. itapurensis and A. teresa, and reduced in A. eimeri, A. pickeli and A. pintoi. Cingulum difficult to observe even using a stereomicroscope in A. eimeri and A. pintoi. Solenomere (Fig. 3 A): elongated and sickle-shaped, rising proximally from the femoral region; shielded by large and broad acropodite process (Fig. 3 A); acropodite process shape species-specific. Female characters: Cyphopods: ovalshaped, situated directly behind the second pair of legs on the third segment; composed of three valves, all of them with bristles; two valves joined by a membrane, with a third apically, appressed against both larger valves (Fig. 3 D).
Distribution. Known from the states of Bahia to Santa Catarina, occurring in the Atlantic rain forest and in the Cerrado area of Brazil (Fig. 19).
Composition. Five species, Atlantodesmus eimeri (Attems, 1898), A. itapurensis (Schubart, 1943), A. pickeli (Schubart, 1946), A. pintoi (Schubart, 1946), A. teresa (Hoffman, 2000), new combination.
description: Published as part of Bouzan, Rodrigo Salvador, Pena-Barbosa, João Paulo P. & Brescovit, Antonio Domingos, 2017, Taxonomic review of the genus Atlantodesmus Hoffman, 2000 (Polydesmida: Chelodesmidae), pp. 269-290 in Zootaxa 4236 (2) on page 271, DOI: 10.11646/zootaxa.4236.2.3, http://zenodo.org/record/321750