cryptic species within the dendrophidion vinitor complex in middle ...

SPECIES IN THE DENDROPHIDION VINITOR COMPLEX N Cadle 187
TABLE 1.
CONTINUED.
Dendrophidion
vinitor Smith, 1941
Infralabials 9 (52)
10 (3)
11 (1)
Dendrophidion
apharocybe New Species
7 (1)
8 (7)
9 (116)
10 (5)
Dendrophidion
crybelum New Species
9 (32)
No. of pale bands on body 51–70 46–69 36–62
60.3 6 4.69 (28) 54.4 6 4.48 (54) 48.2 6 7.53 (13)
The width of the pale neck bands has
been important in distinguishing ‘‘Dendrophidion
vinitor’’ auctorum from other species.
However, neck bands, particularly the
first two behind the head (which are often
broader than other bands), can be very
irregular in outline. Bands on the posterior
two-thirds of the body are more uniform
and narrower than the anterior bands (and
less easily discriminate species). Thus, in
scoring the width of neck bands, I used the
third and fourth band behind the head as
references and counted the scales or
fractions thereof encompassed by the pale
portion of the band (not including the dark
bordering stipple) in the dorsolateral region
at the level of dorsal scale rows 6 and 7. I
counted scales in a horizontal line, not along
the diagonal, as is often counted while doing
dorsal scale counts; this was to minimize the
effect of irregularities in band shape (e.g.,
zigzag or not) on scoring width. Thus, my
summaries of band widths are somewhat
less than some of those encountered in the
literature. For example, Costa Rican ‘‘D.
vinitor’’ are sometimes said to have pale
bands 2–3 scale rows wide (Savage, 2002:
655), whereas in my scorings, most specimens
have bands 1–2.5 rows wide.
Maxillary dentition is similar in the three
species covered in this paper. Teeth gradually
enlarge anterior to posterior, but
typically, four posterior teeth are abruptly
enlarged (and nongrooved). The enlarged
teeth are not offset, and a diastema is absent
(e.g., see Fig. 8). However, there is some
variation within all three species in the
abruptness with which the enlarged posterior
teeth transition to the smaller anterior
series. I assessed some specimens as having
either three or five posterior enlarged teeth
(recognizing some subjectivity as to what
constitutes an ‘‘enlarged’’ tooth). My impression
is that posterior teeth in D. vinitor,
as redefined herein, are not enlarged to the
same degree or as abruptly as in the new
species, D. apharocybe and D. crybelum.
However, this is a subjective impression
only—something that is difficult to quantify
with wet preparations given the apparent
variation. I have not attempted to assess this
more fully, although I comment on some of
the noticeable variation in the species
accounts. Tooth counts are the total number
of maxillary teeth, including empty tooth
sockets and the enlarged posterior teeth.
Everted hemipenes described in detail
and illustrated herein were fully everted in
the field at the time of collection. For
detailed study they were removed from the
specimen and inflated with colored jelly
(Myers and Cadle, 2003); manual eversion
was used for a few specimens for comparative
purposes. Retracted hemipenes were
slit midventrally and pinned flat for study.
In addition to the hemipenes described
in detail, I made reference to others that
were everted to varying degrees and
studied in situ. Hemipenial measurements
were taken with dial vernier calipers to the
nearest 0.1 mm. In the species accounts, I
give brief characterizations of the hemipenes,
emphasizing salient features only.
For ease of comparison, detailed descriptions
of everted and retracted organs of all
three species are deferred to a separate
section at the end. However, because these
species are most notably distinguished by
Bulletin of the Museum of Comparative Zoology harv-160-04-01.3d 11/4/12 19:58:35 187