50834, Hondo Creek, 4 mi. W Bandera; TNHC 797-98, 7 mi. SW Medina.
_Bexar_: ANSP 13447, Helotes; MCZ 4587; USNM 10789, 71009, San
Antonio. _Borden_: BCB 4066, 7 mi. N Vincent. _Brown_: TNHC 7262, 1
mi. E Brownwood. _Comal_: USNM 7700, New Braunfels. _Dawson_: TNHC
21594-95, 10 mi. E Lamesa. _Frio_: USNM 7747, Río Seco. _Gillespie_:
TU 10185, 10187, 10205, Beaver Creek, "near" Doss. _Hays_: AMNH
29950-52, San Marcos. _Kerr_: SM 2553, headwaters Turtle Creek; TU
10142-45, 10147-65, 10176, 10833, Guadalupe River, 9 mi. SE Kerrville.
_Kimble_: BCB 5052-55, 6010, 3 mi. SE Telegraph; TU 14476, South Fork
Llano River, 1.5 mi. SE Telegraph; TU 14485, Llano River, 10 mi. W
Junction. _Lavaca_: SM 2554-55, 2559, 3 mi. NNE Hope. _Llano_: TNHC
12352, TU 16036 (2), Llano River, 2 mi. W Llano. _McMullen_: TNHC
1446, 10 mi. W Simmons, Live Oak County; UMMZ 89915-27, 15 mi. NE
Tilden. _Matagorda_: ANSP 11889, Matagorda. _San Saba_: SM 6106; TU
14419 (6), 14439-40, San Saba River, 11 mi. NNW San Saba. _Tom Green_:
SM 3282, UMMZ 70348, USNM 83690, South Concho River at Christoval.
_Travis_: SM 659-60, 8.5 mi. from mouth of Onion Creek in Colorado
River near Austin; SM 4924, Onion Creek; TNHC 4975, Upper Bull Creek;
TNHC 20257, Marshall Ford Dam. _Victoria_: CM 3118, Black Bayou; UMMZ
92752, San Antonio River, 3 mi. WSW Goliad; USNM 78515-17, Colleto
Creek, Guadalupe River. _County unknown_: ANSP 16717; TNHC 1404.
_Records in the literature._--TEXAS: _Bandera_: 24 mi. WNW Medina
(Brown, 1950:250). _Burnet_: Colorado River (Strecker, 1909:8).
_Gillespie_: 20 mi. N Harper (Brown, _loc. cit._). _Kendall_: Cibolo
Creek at Boerne (Strecker, 1926:8). _Kerr_: Guadalupe River, 3 mi.
above Kerrville (TCWC 474, listed in card file). _Mason_: 12 mi. NE
Mason (TCWC 3303, listed in card file). _Matagorda_: Bay City (Brown,
_loc. cit._). _Real_: (Stejneger, 1944:66). _Wilson_: Cibolo River, 30
or 40 mi. N Sutherland Springs (Strecker, 1935:23).
=Trionyx spinifer pallidus= new subspecies
Pallid Spiny Softshell
Plates 39 and 40
_Holotype._--TU 484, alcoholic adult male; obtained from Lake Caddo,
Caddo Parish, Louisiana on June 27, 1947, by Fred R. Cagle and party
(Pl. 39, lower, left).
_Paratypes._--Forty-two specimens: TU 481, 490, 678 (hatchlings), TU
381, 472, 488 (immature males), TU 475, 478, 486, 1232, 1291, 10170
(adult males), TU 399, 487 (immature females), TU 469 (adult female),
Caddo Lake, Caddo Parish, Louisiana; TU 15818 (immature male), TU
15819 (adult male), Cross Lake, Caddo Parish, Louisiana; TU 1253,
13211 (adult males), TU 13266 (immature female), Sabine River, 8 miles
southwest Merryville, Beauregard Parish, Louisiana; TU 13281-82 (adult
males), TU 13280, 13265 (immature females), TU 13303-04, 13306 (adult
females), Sabine River, 8 miles southwest Negreet, Sabine Parish,
Louisiana; SM 2375 (adult male), Wallace Bayou, De Soto Parish,
Louisiana; TU 1122 (adult male), Lacassine Refuge, Louisiana; UMMZ
92754 (adult male), 5 miles west Iowa, Calcasieu Parish, Louisiana; KU
40174-76, OU 27297 (adult males), OU 27290 (immature female), Lake
Texoma, 2 mi. E Willis, Marshall County, Oklahoma; KU 50832
(hatchling), mouth of Caney Creek, 4 miles southwest Kingston,
Marshall County, Oklahoma; CNHM 15474 (immature female), Kiowa County,
Oklahoma; KU 2966-67 (immature females), KU 2934, 2947 (adult males),
KU 2973 (adult female) Lewisville, Lafayette County, Arkansas.
_Description of holotype._--Carapace circular, widest at level of
posterior edge of hyoplastra; margin entire; dorsal surface
"sandpapery" to touch; pale rim separated from ground color of
carapace by well-defined, slightly ragged, blackish line; pale rim
approximately 2.1 times wider posteriorly (4.7 mm.) than it is
laterally (2.2 mm.); pale rim increasingly narrower anteriorly, absent
in nuchal region; tubercles along anterior edge of carapace triangular
with sharp tips becoming flattened and inconspicuous at level of
insertions of arms; ground color of carapace brownish having pattern
of small whitish tubercles; most whitish tubercles inconspicuous, of
pinpoint size, giving surface of carapace "sandpapery" effect; largest
white tubercles posteriorly, approximately 1.2 millimeters in
diameter; whitish tubercles smaller anteriorly, largest approximately
0.6 millimeters in diameter; whitish tubercles tend to form two
parallel lines coincident with longitudinal sutures of neurals
posteriorly in center of carapace; certain features of bony carapace
evident through overlying skin; carapace highest in region of third
and fourth neurals, forming obtuse, gently sloping, vertebral keel;
undersurface of rear margin of carapace whitish having pinkish tinge
and no markings; maximum length, 16.8 centimeters; greatest width,
14.3 centimeters.
Plastral surface extending slightly farther forward than carapace,
whitish having pinkish tinge and no dark markings; anterior and
posterior lobes rounded, posterior lobe more acutely; certain features
of bony elements of plastron visible through overlying skin; maximum
length, 12.2 centimeters.
Head extended, terminating in flexible snout; septal ridges projecting
into each rounded nostril; tip of snout darkened; jaws open, each
covered by fleshy lips except anteriorly where horny portions exposed;
dark triangular mark in front of eyes, base line uninterrupted,
slightly curved anteriorly, connecting anterior margins of orbits;
eyelids having blackish dots, especially upper, closing eyes; small
blackish dots on dorsal surface of head; pale postocular stripe
dark-bordered, interrupted; pale portion of stripe traversed by black
line; pale subocular blotch margined by broken blackish border; side
of head having contrasting blackish marks on pale background;
postlabial stripe having lower blackish border on right side of head;
chin with ill-defined marks, not contrasting on grayish background;
well-defined, ragged black line on side of neck separating dorsal
coloration from immaculate ventral coloration; small dark dots on
dorsal surface of neck; dorsal surface of head and neck olive or
brownish, becoming paler laterally and toward insertion of neck;
maximum width of head, 2.1 centimeters.
Forefeet and hind feet well-webbed each having five digits; each limb
having nails on first three digits; each forelimb with four
antebrachial scales, three of which have free edge; each hind limb
with two horny scales, one smooth on posterodorsal surface and other
with free edge on posteroventral surface; contrasting pattern of
blackish marks, mostly roundish, on pale background of grayish-white.
Tail terminating in flexible point; penis partly exposed; cloacal
opening extending beyond posterior edge of carapace; tail having
dorsal grayish band flanked by interrupted blackish lines; dark marks
encroaching ventrally at tip of tail.
Undersurface of soft parts of body whitish, with pinkish tinge; dark
marks lacking on soles, present on webbing and palms; dark marks
arranged in linear fashion coincident with digits.
_Range._--Southern Oklahoma, eastern Texas, extreme southwestern
Arkansas, and the western half of Louisiana; Red River drainage and
rivers that drain into the Gulf of Mexico east of the Brazos River
drainage in Texas and west of the Atchafalaya River drainage in
Louisiana. The Brazos River drainage is inhabited by a population that
more closely resembles _pallidus_ than _guadalupensis_ (see comments
under subsection entitled "Remarks"; see map, Fig. 19).
_Diagnosis._--Juvenal pattern of white dots that are usually absent or
inconspicuous, but sometimes distinct and small, on anterior third of
carapace, and not surrounded with dark ocelli; white dots often absent
on posterior half of carapace of hatchlings; white spots, rarely as
large as two millimeters in diameter, not encircled with black ocelli
on adult males; pale rim of carapace less than four times wider
posteriorly than laterally.
_Description._--Plastral length of smallest hatchling, 3.3 centimeters
(KU 50832); of largest male, 16.0 centimeters (SM 2375); of largest
female, 30.5 centimeters (TU 13213).
Surface of carapace in hatchlings uniform pale brown or tan; small
white tubercles absent or inconspicuous on anterior half of carapace,
but evident on posterior half of carapace, sometimes well-defined (TU
481), but usually inconspicuous (TU 678, 490); pale rim of carapace
less than four times wider posteriorly than laterally.
Adult males resembling description of holotype; small whitish
tubercles or dots rarely two millimeters in diameter on posterior half
of carapace, smaller and usually inconspicuous on anterior half of
carapace (TU 13281, 486); well-defined whitish tubercles occasionally
on anterior half of carapace (KU 40174); white tubercles not
surrounded with black ocelli; pattern of white dots seemingly less
contrasting in _pallidus_ than in _guadalupensis_, owing to pale brown
or tan carapace; small tubercles along anterior edge of carapace
equilateral or conical having sharp tips.
Large females usually having pale brown carapaces with slightly
contrasting, brownish, mottled and blotched, patterns; white
prominences often evident posteriorly and anteriorly in middle of
carapace and in nuchal region; tubercles along anterior edge of
carapace equilateral or conical in shape.
Pattern on side of head and snout variable and of no diagnostic value;
postocular stripe uninterrupted having dark borders (UMMZ 92754), or
interrupted having pale segment behind eye (TU 13282); other
variations in pattern shown on TU 10170 and 15818; pale stripes on
snout having dark inner borders that join and form acute angle (TU
381), or lacking dark inner borders and having uninterrupted dark line
connecting anterior margins of orbits (TU 13280); other variations in
pattern on snout shown on TU 1232, 1291 and 15819; specimens
representing illustrations of variation in pattern on snout (Fig. 5 d,
e, f) all from same locality, Lewisville, Lafayette County, Arkansas;
contrasting pattern on side of head of dark marks on pale background;
contrasting pattern of dark marks on dorsal surface of limbs; markings
on hind limbs generally larger than those on forelimbs; small or fine
markings of some specimens reducing contrast in pattern (TU 478, 488);
carapace sometimes having few small blackish dots confined to margin
(CNHM 15474, TU 487, 1253, 13266); ventral surface of plastron and
soft parts of body whitish and usually lacking dark markings; small
blackish marks often occurring on flap of carapace, in region of
bridge, or on chin and throat (TU 399, 469, 475, 472, 13281).
Ontogenetic variation in PL/HW, mean PL/HW of specimens having
plastral lengths 7.0 centimeters or less, 4.15, and exceeding 7.0
centimeters, 5.32; ontogenetic variation in CL/CW, mean CL/CW of
specimens having plastral lengths 8.5 centimeters or less, 1.10, and
exceeding 8.5 centimeters, 1.14; mean CL/PCW, 2.12; mean HW/SL, 1.38
(including subspecies _guadalupensis_); mean CL/PL, 1.36.
_Variation._--In 1953, I casually glanced at a hatchling softshell
from the Calcasieu River drainage in the private collection of Mr.
Wilfred T. Neill; the specimen was considered by Neill (1951:15) as
"... an intergradient one (with the _hartwegi-spinifer_ population in
the lower Mississippi drainage)." The hatchling does deviate from
"typical" _pallidus_ in having darkish flecks posteriorly on the
carapace.
I have seen only one adult male (USNM 94457) from the Sabine River
drainage (Orange County, Texas) that shows characteristics of
_guadalupensis_ (white dots on carapace encircled with small black
ocelli); another adult male (USNM 94456) from the same locality
resembles _pallidus_. Those two USNM specimens were mentioned by Neill
(1951:13) as indicating intergradation with "... the mixed
_spinifera-hartwegi-asper_ populations of Louisiana."
Two adult males (SM 2889, Pl. 40, bottom, left, and TCWC 471, Trinity
River drainage) have blackish ocelli surrounding the white dots on the
posterior part of the carapace; two large females (TU 14402, Pl. 40,
bottom, right, plastral length, 17.5 cm., and TU 14417 plastral
length, 21.3 cm., both from the Trinity River) have contrasting
mottled and blotched patterns with white dots visible on the carapace.
These turtles show alliance with _guadalupensis_.
Some individuals from the Brazos River drainage have features
suggesting those that are characteristic of _guadalupensis_.
Hatchlings may have large white dots on the anterior half of the
carapace (USNM 55601). Adult males may have dusky ocelli surrounding
the white dots on the carapace (TU 14169, 14559.1, 14559.2). The
whitish dots, rarely as large as two millimeters, are never so large
as in _guadalupensis_ (three mm. in diameter), and are usually smaller
anteriorly than posteriorly; TU 14169 has white dots approximately the
same size (1.2 mm.) on the anterior half as on the posterior half of
the carapace. The tubercles on adult males are equilateral or
subconical, usually having sharp tips (TU 14348, 14559.1, 14559.2);
the tubercles on large females are subconical, resembling the end of a
bullet, and, in both sexes the tubercles are less conical than those
on specimens of _pallidus_ from farther east.
Three specimens from the Brazos River drainage are particularly
impressive in their alliance with _guadalupensis_. SM 2556, an adult
male, has large white dots that are encircled with black ocelli on the
posterior half of the carapace, but lacks white dots on the anterior
half. TNHC 14068, a hatchling, has small black dots interspersed with
the larger white dots posteriorly. CNHM 46289 has large white spots on
the carapace that are surrounded with two to four black dots;
scattered black dots also intermix with white spots on the surface of
the carapace (less extensive anteriorly).
Color notes taken from a freshly-killed adult male (KU 47121) from the
Brazos River, seven miles below Whitney Dam, Bosque-Hill county line,
Texas, are: Carapace pale brown or tan bordered by black line, having
pale lemon yellow rim; yellowish-cream spots on carapace faintly
surrounded with black stippling; dorsal surface of soft parts of body
olive having black marks and patches of grayish; webbing on limbs
having golden or yellowish hue, brighter distally; interorbital region
brown; black-bordered, postocular stripe orange-cream; snout and side
of head olive having pale areas of orange-cream; iris cream having
black stripe; yellowish at juncture of dark dorsal and pale ventral
coloration with orangish tinge on forelimbs and head; tail pale brown
or tan, flanked by black borders that suffuse laterally into
lemon-yellow; undersurface whitish, pale yellow on neck, bluish-gray
on throat.
_Comparisons._--_T. s. pallidus_ most closely resembles _T. s.
guadalupensis_, but can be distinguished from that subspecies in
having small white tubercles, rarely two millimeters in diameter, on a
pale background, that are not surrounded by blackish ocelli, and are
usually absent, or not conspicuous on the anterior third of the
carapace in adult males; also there are usually no conspicuous white
tubercles or dots on the anterior third of the carapace in hatchlings.
Many adult males of _pallidus_ from the Brazos and some from the
Trinity River drainages often have dusky or black ocelli surrounding
the white dots posteriorly on the carapace; males from these river
systems may be distinguished from _guadalupensis_ in having most, if
not all, white dots on the anterior half of the carapace smaller than
those posteriorly, and a pale brown carapace (in life, usually darker
in _guadalupensis_). _T. s. pallidus_ (and _guadalupensis_) is
distinguished from _emoryi_ in lacking a widened pale rim posteriorly,
and in having small white spots on the anterior half of the carapace.
_T. s. pallidus_ resembles _guadalupensis_ and _emoryi_ in having
white spots on the carapace in adult males. _T. s. pallidus_ differs
from _spinifer_, _hartwegi_ and _asper_ in lacking blackish dots or
ocelli that occur in the center of the carapace. _T. s. pallidus_
resembles _emoryi_ but differs from _guadalupensis_ in lacking black
ocelli surrounding the white spots. _T. s. pallidus_ resembles
_spinifer_, _hartwegi_ and _asper_ but differs from _guadalupensis_
and _emoryi_ in having tubercles along the anterior edge of the
carapace that are conical having sharp tips in males, and conical in
large females.
_T. s. pallidus_ resembles _spinifer_ and _hartwegi_ but differs from
the other subspecies in having a narrow head. _T. s. pallidus_ differs
from _emoryi_ but resembles the other subspecies in having a wider
carapace. _T. s. pallidus_ resembles _emoryi_ and _guadalupensis_, and
differs from the other subspecies in having the carapace widest
farther posterior than one-half the length of the carapace. The snout
of _pallidus_ and _guadalupensis_ is shorter than in _spinifer_ and
_hartwegi_, but longer than in _emoryi_. _T. s. pallidus_ differs from
_asper_ but resembles the other subspecies in having a relatively long
plastron.
_Remarks._--Intergradation of the subspecies _pallidus_ and
_guadalupensis_ is of a clinal nature in which populations
successively show a gradual resemblance to _guadalupensis_ from
western Louisiana and eastern Texas westward to central Texas. Because
the sharpest break in this cline of characters occurs between the
Colorado and Brazos River drainages, the turtles living in the Brazos
River drainage and eastward are referred to _pallidus_, whereas those
in the Colorado River drainage and westward are referred to
_guadalupensis_. For further comments on intergradation between these
two subspecies, see the account of _T. s. guadalupensis_.
Taylor (1935:217-18) reported on some specimens of _Amyda spinifera_
that were obtained by Mr. R. E. McEntyre in "... the spring and summer
of 1926, chiefly about Lewisville, Lafayette County (Arkansas)." Of
the catalog numbers listed by Taylor from Lewisville, 58 (KU,
alcoholic) represent _pallidus_. Three, having the same locality data,
have features that are characteristic of _hartwegi_. KU 2944 (one of
three specimens having this catalog number) is a female having a pale,
mottled and blotched carapace approximately one foot in length; there
are remnants of two dark ocelli, and many widely-scattered,
well-defined dark spots near the periphery of the carapace. KU 2963
(one of three specimens having this catalog number) is an adult male
that has solid, blackish dots on the entire surface of the carapace.
KU 2964 (one of two specimens with this catalog number) is an adult
male that has ocelli approximately five millimeters in diameter on the
carapace (indistinct in center of carapace).
Lewisville is situated in the drainage basin of the Red River and is
approximately eight miles east of the Red River and 30 miles west of
the westernmost tributary of the Ouachita River drainage. _T. s.
pallidus_ occurs in the Red River drainage; _hartwegi_ occurs in the
Ouachita River drainage. Perhaps there is intergradation between
_pallidus_ and _hartwegi_ in the intervening streams. There is no data
to indicate from which river or stream each specimen obtained by
McEntyre came; one would presume that all specimens came from the Red
River drainage. But this is not certain. Certainly the 47 specimens
designated herein as _pallidus_ came from the Red River drainage. I
suspect that KU 2944, 2963 and 2964 were obtained from tributaries of
the Ouachita River drainage.
_T. s. pallidus_ intergrades with the _spinifer-hartwegi_ population
where the Red River joins the Mississippi River in the lower
Mississippi Valley in Louisiana. The majority of 13 juvenal specimens
from the Red River near Shaw, Concordia Parish, Louisiana (USNM
99862-69, 99871-75), resemble _pallidus_ in having inconspicuous white
tubercles on a pale brown carapace. The white tubercles are
conspicuous in USNM 99871. Some specimens have a few small dark dots
confined to the margin of the carapace, as do some "variant"
individuals from well within the geographic range of _pallidus_. USNM
99865 is referred to _hartwegi_ because the carapace is covered with
dark ocelli approximately one millimeter in diameter. Some specimens
from farther west in the Red River drainage are referred to
_hartwegi_. One (USNM 100420) of three from Natchitoches Parish,
Louisiana (TU 5763, USNM 100420-21), having blackish dots on the
carapace, is applicable to _hartwegi_. Of two turtles from Grant
Parish, Louisiana (TU 5647, 12735), only 12735 has dark dots and
ocelli (_hartwegi_). One specimen from Rapides Parish, Louisiana (TU
14040), having dark dots on the entire surface of the carapace, is
referred to _hartwegi_.
Most specimens from the lower Atchafalaya River drainage are referable
to _pallidus_. Eastward, intergradation occurs with the
_spinifer-hartwegi_ population; USNM 100089-90 from Assumption Parish,
near Napoleonville, Louisiana, are referred to _pallidus_. TU 11983,
from Bayou Lafourche, Raceland, La Fourche Parish, and TU 13698.11,
from Bayou Gauche in St. Charles Parish, Louisiana, are juvenal males
that combine the characteristics of _pallidus_ and _hartwegi_; the
carapaces are covered with blackish spots and posteriorly have
distinct whitish dots. The population in the Atchafalaya River more
closely resembles _pallidus_ than it does _hartwegi_ or _spinifer_. In
former times the Atchafalaya River was presumably continuous solely
with the Red River (inhabited by _pallidus_). Now, these two rivers
and the Mississippi River are interconnected in east-central
Louisiana. A large volume of water of the Mississippi drainage is
conveyed to the Gulf of Mexico by the Atchafalaya, and someone has
said that by approximately 1975, unless man interferes, two-thirds to
three-fourths of the total volume of water of the Mississippi River
will be drained by the Atchafalaya. One can expect, therefore, an
increase in the influence of the _hartwegi-spinifer_ population in the
Atchafalaya River drainage.
_Specimens examined._--Total 270, as follows: ARKANSAS: _Lafayette_:
KU 2930-37, 2939-40, 2942, 2944 (two of three specimens bear this
catalog number), 2945-57, 2958 (2), 2959-61, 2963 (two of three
specimens bear this catalog number), 2964 (one of two specimens bears
this catalog number), 2965-73, 2987-89, 3056, Lewisville.
LOUISIANA: _Acadia_: USNM 100151-59, Mermentau River. _Assumption_:
USNM 100089-90, Bayou Lafourche, "near" Napoleonville. _Beauregard_:
TU 1231-32, 1253-55, 1291, 13211, 13266, Sabine River, 8 mi. SW
Merryville. _Bienville_: TU 5649-50, Lake Bistineau. _Caddo_: TU 381,
397-99, 469-72, 474-90, 678, 10170, Caddo Lake: TU 15818-19, Cross
Lake. _Calcasieu_: UMMZ 92754, 5 mi. W Iowa. _Cameron_: TU 1122,
Lacassine Wildlife Refuge. _Concordia_: USNM 99862-64, 99866-69,
99871-75, Red River, "near" Shaw. _De Soto_: SM 2374-75, Wallace
Bayou. _Grant_: TU 5647, Lake Iatt. _Iberville_: USNM 83985, 2 mi. E
Mounds; USNM 100239-41, Grand Lake west of White Castle; USNM 100380,
Plaquemine; USNM 100412, 100414-15, 100419, Spanish Lake, "near" St.
Gabriel. _Jefferson Davis_: Calcasieu River drainage, WTN (no number,
see page 524). _Natchitoches_: TU 5763, Bermuda; USNM 100421, "near"
Natchitoches. _Sabine_: TU 13210, 13212-13, 13265, 13280-82, 13303-06,
Sabine River, 8 mi. SW Negreet. _St. Martin_: USNM 100160, Bayou
Chene; USNM 100650, Atchafalaya. _St. Mary_: USNM 100395-97, 100404,
100409-10, Berwick Bay near Morgan City.