Potomotyphlus Taylor, 1968

Maciel, Adriano O. & Hoogmoed, Marinus S., 2011, Taxonomy and distribution of caecilian amphibians (Gymnophiona) of Brazilian Amazonia, with a key to their identification, Zootaxa 2984, pp. 1-53 : 35-37

Potomotyphlus Taylor, 1968 (monospecific genus)

Potomotyphlus kaupii Berthold, 1859

Caecilia kaupii Berthold, 1859: 181 .

Chthonerpeton microcephalum: Miranda-Ribeiro, 1937: 66 ; Miranda Ribeiro 1955: 407

Typhlonectes kaupii: Dunn 1942: 537

Potomotyphlus kaupii: Taylor, 1968: 257 ; Frost, 1985: 640; Lescure & Marty, 2000: 306; Caramaschi, U., & Pombal Jr., 2000: 49; Marty et al., 2007a 35; Marty et al., 2007b: 38; Galatti et al 2007: 93; Frost, 2008.

Diagnosis. Maximum known TL 695 mm ( Taylor, 1968). PA 83–102. SG absent. Head slightly compressed ventrally, narrower than most of body. Eye in open orbit, visible or not under skin. Small anterior tentacles, below nostrils, near margin of mouth, much closer to nostrils than corner of mouth, not visible from above. Nostrils subtriangular, visible or not from above. Body laterally compressed. A dorsal keel or fin, at least on posterior half of body. Marked sexual dimorphism in terminal region, females having narrower and more pointed terminus. Vent disk elongate anteriorly, rounded posteriorly, may or may not be depressed, surrounded by fleshy folds of skin in both sexes. Paired anal papillae present or absent. Dermal and subdermal scales absent. Tongue anteriorly completely attached to mandibular mucosa; two large narial plugs. Four series of teeth, all monocuspid.

Description. TL 28.8–68.1 times (41 ± 8.7; n = 41) BW. Head small, narrower than body and slightly depressed. Snout projecting distinctly beyond mouth. Eye visible in most specimens, indistinct in some, independently of body size. Nuchal grooves may be indistinct or distinct laterally and ventrally. Body compressed, deeper than wide. Primary annular grooves interrupted dorsally. Last 3–6 annuli only distinct laterally. No annuli from approximately level of vent to terminal tip of body. Vent disk extended anteriorly; some anterior denticulations are elongate (e.g. two in MPEG 9672). AD 7–11 (9 ± 0.7; n = 50); generally an approximately similar number in posterior and anterior edge of vent (e.g. four anterior and five posterior ones in MPEG 2888). Paired anal papillae only observed in two of 24 male specimens of a total of 57 specimens studied. PMT maximally 60, no distinct variation in size; extending posteriorly of level of choanae, as PPT. PPT maximally 53; smaller than PMT. DT maximally 64, approximately same size as PMT; posterior teeth smaller. ST at most 12, approximately same size as PPT.

Color. In life grayish or brownish. Grooves along body may be darker than body. Marty et al. (2007a) described the color of a freshly dead female as: body blue-grey, paler on head. Underside white-blue. Grooves of primary annuli darker than rest of body. Color of second specimen (not collected) in life was described as dorsally grey, changing to blue on head and a whitish ventral coloration. A color photograph of a live specimen ( Marty et al., 2007b) agrees with the description provided by Marty et al. (2007a).

Variation. Sexual dimorphism in vent region: males with disc more sunken than large females, disc of small females not depressed. For variation see description and Table 12.

Distribution. Amazon and Orinoco drainages in northern South America: Brazil (states of Acre, Amapá, Amazonas, Goiás, Pará and Roraima), Colombia, Ecuador, French Guiana, Peru and Venezuela ( Fig. 20 ). Lescure & Marty (2000: 306) doubted the locality “Cayenne of a specimen in the museum in Brussels, not including this species in the herpetofauna of French Guiana, but recent reports ( Marty et al., 2007a, 2007b) have conformed its presence in the Oyapock river, between French Guiana and Amapá, Brazil.

Natural history. Marty et al. (2007a) report on a specimen that was collected at night in shallow water at the edge of a river in a cataract area and concluded that the species thus could live in running water. In the region of Belém, Brazil, specimens are regularly found in native shrimp traps called “matapi by local people.

Tucuruí Macapá R. Negro R. Branco Roraima Santarém Marchantaria Serra dos Trombetas UHE Melgaço + Serra da region AC AM Carajás PA Balbina Xingu Mesa

TL 169-370 555 (1) 453.8 (1) 455 (1) 325-450 36-460 460-490 (2) 255 (1) 332 (1) 242 (1) 173-395 (2) 183-310 247.2 ± 52.1 (35) (2) 403.2 ± 41.8 (2)

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HW 3.7-6.9 9.2 (1) 6 (1) 8.1 (1) 5.9 (2) 5.5-6.4 6.7-6.9 (2) 5 (1) 5.2 (1) 5.2 (1) 4.5-6 (2) 4.5-5.3 (2) 5.2 ± 0.7 (36) 5.9 ± 0.4 (3)

HL 5.3-9.7 13.3 (1) 10.4 (1) 11.4 (1) 9.4 (2) 9.1-10.3 10-10.2 (2) 8.2 (1) 8.3 (1) 8 (1) 7-9.3 (2) 7.5-9.9 (2) 7.5 ± 1 (36) 9.7 ± 0.5 (3)

HH 2.1-4 5.4 (1) 3.6 (1) 4.8 (1) 3.6-3.7 3-4.3 4.4-4.7 (2) 2.9 (1) 3.7 (1) 2.7 (1) 3.1-4 (2) 2.7-3.5 (2) 3 ± 0.4 (36) (2) 3.7 ± 0.6 (3)

BW 4.3-11.3 10.7 (1) 6.7 (1) 15.8 (1) 7.9-9.1 10.4-11.8 (2) 5.7 (1) 8.6 (1) 6.2 (1) 4.6 (1) 3.7-8.6 (2) 6.6 ± 1.9 (24) (2)

BH 4.8-15.7 24.2 (1) 12.2 (1) 18.4 (1) 13.1-14.2 16-17 (2) 10 (1) 9.2 (1) 10 (1) 6.8 (1) 6.3-12.2 9.1 ± 3 (25) (2) (2)

WNC 3.6-6.9 9.2 (1) 6.5-6.7 6.1-7 7.2-7.5 (2) 5.4 (1) 6.7 (1) 5.8 (1) 4.8-6.8 (2) 5.7 ± 0.8 (23) (2) 6.4 ± 0.4 (3)

WTR 2.1-7 4.9 (1) 3.9 (1) 10.4 (1) 5.7-5.8 4-6 7.8-8.2 (2) 3.2 (1) 5.7 (1) 5.1 (1) 3 (1) 2.8-4.7 (2) 4.1 ± 1.3 (26) (2) 5.1 ± 1 (3)

WV 2-7.2 5.7 (1) 3.9 (1) 11 (1) 4.2-4.7 3.5-3.8 (2) 8.5-8.9 (2) 2.5 (1) 4.3 (1) 5.9 (1) 2.3-3.5 (2) 2.2-2.8 (2) 3.7 ± 1.3 (31) (2)

EE 2.9-4.5 3.8 (1) 4.7 (1) 3.6-3.9 3.9-4.1 (2) 3.5 (1) 4.2 (1) 3.5 (1) 2.9-3.9 (2) 3-3.8 (2) 3.6 ± 0.4 (19) 3.7 ± 0.1 (3)

EN 1.7-3 3.1 (1) 3.3 (1) 2.9-3 3.5-3.6 (2) 2.4 (1) 2.3 (1) 2.2 (1) 1.9-3.1 (2) 2.1-2.6 (2) 2.3 ± 0.3 (18) 2.9 ± 0.05 (3)

ET 1-2.3 2.1 (1) 2.6 (1) 1.8-2.1 2.3 (1) 1.7 (1) 1.6 (1) 1.5 (1) 1.2-2.2 (2) 1.6-1.8 (2) 1.6 ± 0.3 (18) 2 ± 0.1 (3)

EMM 0.9–1.5 1.8 (1) 1.2 (1) 1.7 (1) 1.3–1.5 1.6–1.7 (2) 1.1 (1) 1.2 (1) 1.1 (1) 1.1–1.6 (2) 1–1.3 (2) 1.1 ± 0.1 (20) 1.38 ± 0.1 (3)

Continued next page… Tucuruí Macapá R. Negro R. Branco Roraima Santarém Marchantaria Serra dos Trombetas UHE Melgaço + Serra da Mesa region AC AM Carajás PA Balbina Xingu 1.2–2.7 3.2 (1) 2.5 (1) 2.6 (1) 2.2–2.4 2.5–2.6 2.6–2.7 (2) 2 (1) 2 (1) 2 (1) 1.6–2.4 (2) 1.7–2.1 (2) 1.8 ± 0.2 (36) (2) 2.56 ± 0.05 (3)

0.4–1.8 1.6 (1) 0.9 (1) 1.1 (1) 0.7–0.8 0.6–1.1 0.7–1.3 (2) 0.7 (1) 0.5 (1) 0.6 (1) 0.5–0.7 (2) 0.4–0.8 (2) 0.6 ± 0.2 (36) (2) 0.9 ± 0.2 (3)

TCM 2.1–4.2 5.4 (1) 4.3 (1) 5.7 (1) 3.7 (2) 3.6–4.5 4.2–4.8 (2) 3.3 (1) 3.5 (1) 3 (1) 2.6–4.2 (2) 3.2–3.3 (2) 2.8 ± 0.5 (36) 4.1 ± 0.4 (3)

TMM 0.7–1.2 1.8 (1) 1.1 (1) 1.5 (1) 1.2 (2) 1.1–1.4 1.4–1.5 (2) 0.9 (1) 0.8 (1) 1 (1) 0.8–1.2 (2) 0.8–1.2 (2) 0.9 ± 0.1 (36) 1.2 ± 0.1 (3)

1.3–2.7 3.3 (1) 2.2 (1) 2.9 (1) 2.4–2.5 (2) 2.5 (3) 2.3–2.7 (2) 2 (1) 2.3 (1) 2.1 (1) 1.6–2.3 (2) 1.7–2.2 (2) 2 ± 0.2 (36)

NMM 0.9–1.6 2.1 (1) 1.4 (1) 1.9 (1) 1.5 (2) 1.4–1.7 1.8–2.1 (2) 1.2 (1) 1 (1) 1 (1) 1.2–1.4 (2) 1.2–1.5 (2) 1.1 ± 0.1 (36) 1.5 ± 0.1 (3)

83–97 93 (1) 100 (1) 87 (1) 93-98 (2) 92–102 100–101 (2) 86 (1) 90 (1) 83 (1) 91–96 (2) 88–91 (2) 89.5 ± 3 (36) 97.2 ± 4.1 (4)

7–11 9 (1) 9 (1) 9–10 (2) 9–10 9 (2) 9 (1) 9 (1) 8 (1) 9 (2) 9–10 (2) 8.8 ± 0.8 (29) 9.6 ± 0.5 (3)

0–1 0 (1) 0 (1) 0–1 (2) 0 (4) 0–1 (2) 0 (1) 0 (1) 0 (1) 0–2 (2) 0 (2) 0.2 ± 0.4 (36)

29–45 54 (1) 49 (1) 36–39 (2) 32–36 (2) 30 (1) 35 (1) 32 (1) 38 (1) 32–40 (2) 39–44 (2) 35.9 ± 4 (28)

28–36 44 (1) 48 (1) 25 (1) 28 (1) 30 (1) 40 (1) 31.8 ± 3.8 (5)

22–40 50 (1) 48 (1) 34 (2) 38 (1) 36 (1) 26 (1) 36 (1) 28–35 (2) 37–42 (2) 30 ± 5.2 (25)

4–11 7 (1) 11 (1) 7–8 (2) 9 (1) 10 (2) 8 ± 1.9 (14)

/BW 29.8–56.1 51.8 (1) 68.1 (1) 28.7 (1) 35.7–56.9 41.5–42.9 (2) 44.7 (1) 38.6 (1) 39 (1) 37.6 (1) 36–49.4 (2) 38.9 ± 7.9 (23) (2)

Figures

FIGURE 20. Distribution of Potomotyphlus kaupii. Open symbols represent data from literature; closed symbols specimens analyzed in this study. 1 Pucayac, Pastaza, Ecuador (Taylor & Peters, 1974); 2 Río Itaya, San Antonio, Iquitos, Peru (Taylor, 1968); 3 Río Ampiyac, near Pebas, Iquitos, Peru (Taylor, 1968); 4 Río Meta, Puerto López, Colombia (Lynch, 1999); 5 La Macarena, Meta, Colombia (Lynch, 1999); 6 Río Caquet, La Pedrera, Amazonas, Colombia (Lynch, 1999); 7 Type Locality, Angostura, Ciudad Bolívar, Venezuela (Taylor, 1968); 8 Rio Branco, Acre, Brazil; 9 Cachoeira do Bem Querer, Roraima, Brazil; 10 UHE Balbina, Presidente Figueiredo, Amazonas, Brazil; 11 Ilha Marchantaria, Amazonas, Brazil; 12 Cachoeira Porteira, Oriximiná, Pará, Brazil; 13 Santarém, Pará, Brazil; 14 Macapá, Amapá, Brazil; 15 Melgaço, Pará, Brazil; 16 Abaetetuba, Pará, Brazil; 17 Belém, Pará, Brazil; 18 Acará, Pará, Brazil; 19 Tucuruí, Pará, Brazil; 20 Jacundá, Pará, Brazil; 21 Serra dos Carajás, Pará, Brazil; 22 Usina Hidroeletrica Serra da Mesa, Goiás, Brazil; 23 Cayenne, French Guiana; 24 Oyapock river, Georges-del`Oyapock, French Guiana (Marty et al., 2007 a).