Morphological variation of Trilepida macrolepis (Peters 1857), with reappraisal of the taxonomic status of Rena affinis (Boulenger 1884) (Serpentes: Leptotyphlopidae: Epictinae)
Author
Pinto, Roberta R.
Author
Fernandes, Ronaldo
text
Zootaxa
2017
4244
2
246
260
journal article
36238
10.11646/zootaxa.4244.2.6
bef234e7-eadb-483e-b574-e379c061a9fb
1175-5326
400886
4945BA57-0971-4F7B-B866-DAF157D25A08
Trilepida macrolepis
(
Peters 1857
)
Figs. 3–4
Stenostoma macrolepis
Peters 1857
:402
.
Stenostoma
(
Tricheilostoma
)
macrolepis
—
Jan 1861
:190.
Glauconia macrolepis
—
Boulenger 1893
:69
.
Leptotyphlops macrolepis
—
Ruthven 1922
:64
.
Leptotyphlops ihlei
Brongersma 1933
—
Orejas-Miranda 1966
:1
.
Stenostoma
(
Tricheilostoma
)
macrolepis
—
Loveridge 1957
:246
.
Tricheilostoma macrolepis
—Adalsteinsson
et al
. 2009:11.
Trilepida macrolepis
—
Hedges 2011
:63
.
Lectotype
.
Adult specimen,
ZMB
1434
(
Fig. 3
) formerly from “
Caracas
and
Puerto Cabello
,
Venezuela
; restricted to
Puerto Cabello
(1025'23 N, 6800'45 W),
Carabobo
State,
Venezuela
by
Orejas-Miranda
(1967)
.
FIGURE 3.
Dorsal (A) and ventral (B) views of body and dorsal (C), lateral (D), and ventral (E) views of head of the lectotype of
Trilepida macrolepis
(ZMB 1434). Photos by F. Tillack (ZMB).
Paralectotypes
.
Adult,
ZMB
5294
(
Fig. 4
A), from
Puerto Cabello
,
Carabobo
State,
Venezuela
.
Adult
, undetermined sex
,
ZMB
5722
(
Fig. 4
B), from “
S. Amerika
(=
South
America) (see remarks).
Diagnosis.
Trilepida macrolepis
can be distinguished from all congeners by the following combination of characters: (1) snout truncate in dorsal and ventral views and rounded on lateral view; (2) supraocular present; (3) rostral subtriangular in dorsal view not reaching the anterior limit of ocular scale; (4) rostral similar in size as supranasals; (5) frontal scale longer than other middorsal cephalic shields, and smaller than supraoculars; (6) three supralabials (2+1); (7) four infralabials; (8) scales at midtail 10; (9) fused caudals present; (10) middorsals
211–243 in
females and
218–243 in
males; (11) midventrals
217–225 in
females and
204–221 in
males; (12) subcaudals
16– 21 in
females and
18–24 in
males; and (13) seven dorsal scales rows with dark brown to black pigmentation in contrast with seven pale brown ranging to brown covering the center of scales in ventral rows with lighter borders.
FIGURE 4.
General view of the paralectotypes of
Trilepida macrolepis
(A—ZMB 5294; B—ZMB 5722). Scale = 5 mm. Photos by F. Tillack (ZMB).
Comparisons.
Trilepida macrolepis
differs from
T. brasiliensis
by having supraocular scales (vs. absent of supraocular); differs from
T. guayaguilensis
by having fused caudals (vs. absence of fused caudals); differs from
T. affinis
,
T. dimidiata
,
T. jani
, and
T. nicefori
by having three supralabials (vs. two supralabials); differs from
T. pastusa
by having four, rarely six infralabials (vs. five infralabials); differs from
T. joshuai
by having snout rounded on lateral view (vs. truncate); differs from
T. fuliginosa
and
T. koppesi
by having snout truncate on dorsal and ventral views (vs. rounded); differs from
T. macrolepis
from
T. anthracina
by having frontal smaller than supraocular (vs. frontal longer than supraocular); differs from
T. brevissima
by having frontal longer than other middorsal cephalic shields (vs. with similar size); differs from
T. dugandi
by having rostral subtriangular in dorsal view (vs. semicircular); differs from
T. salgueiroi
by having rostral as long as supranasals (vs. shorter than supranasals). Refers to Table 1 for additional meristic and color differences between congeners
Coloration in preservative.
Body with seven dorsal scale rows dark brown to black, darkened pigmented on the center of each scale and bordered by lighter edges (pale brown); venter with seven pale brown to brown center of scales bordered cream edges; coloration of the head follows the body pattern; lower limits of supralabials cream; cloacal shield and terminal spine brown.
Variation.
Middorsal scales 221–255 (241.1 11.3,
n
= 16) in females and 211–247 (231.2 8.7,
n
= 22) in males; midventrals 214–237 (225.7 8.6,
n
= 13) in females and 201–228 (214.1 7.4,
n
= 16) in males; subcaudals 17–22 (19.4 1.3,
n
= 16) in females and 16–24 (20.5 2.3,
n
= 22) in males; TL
145–378 mm
(
287.7 mm
63.7,
n
= 16) in females and
119–321 mm
(220.0 mm 59.0,
n
= 22) in males; TL/TAL ratio 11.3–15.5 (13.7 1.1,
n
= 16) in females and 8.5–15.6 (12.5 1.9,
n
= 22) in males; TAL 6.4–8.9% from TL (7.4% 0.0,
n
= 16) in females and 6.3– 11.7% (8.2% 0.0,
n
= 22) in males; TL/MB ratio 32.2–57.7 (48.4 7.0,
n
= 16) in females and 37.1–68.3 (48.6 8.5,
n
= 22) in males; TAL/MT ratio 3.8–6.7 (4.9 0.7,
n
= 14) in females and 4.3–6.6 (5.3 0.6,
n
= 16) in males; relative eye diameter 1.1–1.9 (1.5 0.2,
n
= 13) in females and 1.3–2.1 (1.7 0.3,
n
= 14) in males; relative rostral width 0.3– 0.4 (0.4 0.04,
n
= 9) in females and 0.3–0.4 (0.4 0.03,
n
= 11) in males; temporal not distinct (58%,
n
= 14) or distinct (42%,
n
=10).
Salazar-Valenzuela
et al.
(2015)
reported a single specimen with six infralabials (DHMECN 11400), and other with 12 scale rows at mid-tail (QCAZ 10247).
Sexual dimorphism.
We found secondary sexual dimorphism in the number of middorsal scales (
F
1, 36 = 9.3,
P
<0.01,
n
= 38), midventral scales (
F
1, 27 = 15.4,
P
<0.001,
n
= 29), and TL/TAL ratio (
U
= 103.0,
P
<0.05,
n
= 38) in which females have highest values. Males had the larger proportions of TAL considering the TL (
U
= 103.0,
P
<0.05,
n
= 38). No sexual dimorphism was found in the number of subcaudals scales (
U
= 119.0,
P
= 0.09,
n
= 38). Although, males have relatively larger eyes than females, this difference was not significant (
F
1, 25 = 3.0,
P
= 0.09,
n
= 27).
Geographic distribution.
Trilepida macrolepis
is distributed in the trans-Andean portion of
Magdalena
Valley and
Eastern
Cordillera of
Colombia
to cis-Andean lowlands at rain and dry forests of
Suriname
,
French Guiana
,
Colombia
,
Venezuela
, and
Brazil
from
0–1,000 m
above sea level (
Fig. 2
).
Remarks.
Bauer
et al.
(2002)
analyzed the original type labels in the ZMB collection, and found an error in the type locality indicated in the original description of
T. macrolepis
. According to
W. Peters (1857)
, the type locality of
Stenosoma macroleps
was Caracas and Puerto Cabello, Venezuela. However no specimen among the syntypes is labeled as being from Caracas (see
Bauer
et al.
2002
). On the other hand, Puerto Cabello was an important port located about
75 km
west from the Caracas (today), where most collected specimens were shipped to the main museums in Europe in the beginning of the last century. Puerto Cabello maybe not corresponds to real locality of collection, as already know for other reptiles and amphibians species also described from the same locality (see
Rivas & Manzanilla 1999
;
Rivas
et al.
2012b
).
Rivas
et al.
(2012b)
also questioned the possibility of some species were actually collected in the mountains surrounding Puerto Cabello, at a nearby locality such as within San Esteban National Park.