Two new species of the genus Platymantis (Amphibia: Ranidae) from Luzon Island, Philippines

8 Pages·1998·3.3 MB·English

by  Angel C Alcala

PROCEEDINGS
OF THE NOV 1 9 19S,
CALIFORNIA ACADEMY OF SCIENCES
Vol. 50, No. 17, pp. 381-388, 2 figs., 1 tables. November 6, 1998
TWO NEW SPECIES OF THE GENUS PLATYMANTIS
(AMPHIBIA: RANIDAE) FROM LUZON ISLAND, PHILIPPINES
By
Angel C. Alcala
Commission on HigherEducation, DAPbuilding, San MiguelAvenue,
PasigCity, Philippines
Walter C. Brown
DepartmentofHerpetology, CaliforniaAcademyofSciences
Golden GatePark, San Francisco, California 94118
and
Arvin C. Diesmos
CollegeofArtsandSciences, UniversityofthePhilippinesatLosBahos
College, Laguna, Philippines
Twonew speciesoffrogs,PlatymantispygmaeusandP.naomii,aredescribedfrom LuzonIsland,
Philippines.ThespeciesaredifferentfromotherPhilippinespeciesofthedorsalisGroupintheir
maleadvertisementcallsandothercharacteristicsgiveninthediagnoses.
Received March5, 1998.Accepted May28, 1998.
Thetwospecies,PlatymantispygmaeusandP. MATERIALSANDMETHODS
naomii, described here are in the Platymantis
dorsalis Group. They were first identified in the Materials examined include holotypes of
field by their distinct advertisement calls. The Platymantisdorsalis, meyeri, andmimulusofThe
dorsalisGroup,aspresentlydiagnosed, isdiffer- dorsalis Group ofPlatymantis from the Philip-
entiated from other Philippine Groups (hazelae pinesandparatypesofPlatymantisparkeri from
Group andguentheri Group) on the basis of: (1) Bougainville Island in the Solomons,
digitsaboutasdeepasbroad, (2)relativelyundi- Morphometric characters: Snout-vent length
lated, rather than broadly dilated finger and toe (SVL), head length (HL), head width (HW),
disks, and (3) blunt or pointed terminal pha- snoutlength(SnL),diameterofeye(ED),diame-
langes, ratherthan T-shaped terminal phalanges ter of tympanum (TD), tibia length (TiL), and
(Brown, Brown and Alcala 1997). third finger length (3FL) from proximal edge of
basal tubercle, were measured to the nearest0.1
mmusingaHeliosdialcaliper.Othernon-metric,
morphological characters include webbing of
[381]
382 PROCEEDINGS OFTHECALIFORNIA ACADEMY OF SCIENCES
Volume 50, No. 17
fingers and toes, skin ornamentation, shape of nally behind tympanum; lores moderately
snout,shapeofterminalphalanges,colorpattern, oblique, concave; vomerine teeth only slightly
vomerineteeth, andtuberclesonvariouspartsof protruding, widely separated; fingers not
thebody. Advertisementcallswererecordedand webbed, with small, shallow-grooved disks;
analyzed using a Kay Electrics SonaGraph first, second, and fourth fingers about equal in
(Model #550) with a wide-band filter and SIG- length and shorter than third; 3FL 10-13% of
NAL Sound Analysis System software. SVL; subarticular tubercles prominent but not
pointed; one row of supernumerary tubercles;
Systematic Section inner and middle metacarpal tubercles large,
oval; outertubercle small, oval; hind limb mod-
Platymantis pygmaeus, new species erately long, TiL 46-53% of SVL; toes with
minute webs at base; disks of toes distinctly
—
Holotype. NMPH 6255,anadultmale,col- larger than those of fingers; subarticular tuber-
lected in disturbed Dipterocarp Forest at 55-65 clesoftoesmoreprominentthanthoseoffingers;
m in the Northern Sierra Madre Natural Park in innermetatarsal tubercle largerthan outer, elon-
Sitio Natapdukan, Barangay Didian, Municipal- gate; outer round, strongly protruding; plantar
ity of Palanan, Isabela Province (16°57.93'N, area smooth; dorsum, head, snout, eyelids, and
122°24.23'E), Luzon Island, by A. C. Diesmos, limbs generally smooth, with few tubercles on
24 March 199—7. dorsum and eyelids in occasional specimens;
Paratypes. CAS 204762-64 at the type lo- throat, bell—y, and thighs smooth.
cality; CAS 204765-66, NMPH 6456-60, at COLOR. In preservative, dorsal ground
Bios, Barangay Reina Mercedes, Maconacon, colordirty white to light brown with some dark
Isabela Province, within 50 km oftype locality, blotches; head and snout generally darker than
collectedbyA. C. Diesmos,M—arch-April, 1997. posteriorpart; tympanum with dark figure; dark
Description of Holotype. A mature male crossbars on forelimbs and hind limbs; dark,
(measurements in mm): SVL 15.2, HL 5.5, HW irregularspot on proximal antero-ventral partof
6.0, SnL 2.4, ED 2.1, TD 1.5, TiL 7.5, 3FL 1.7; upper arm and adjacent part ofchest; in lighter-
dorsum brown, with darkerblotch in middle; an colored specimens, a dark brown oval ring sur-
oblong darker spot surrounding anal opening; rounds the anal opening. Side ofbody posterior
dorsum and venter smooth; a white oblique line to forelimb with areolation in most specimens.
composedofaboutthreetuberclesatthepostero- Belly and ventral parts of limbs dirty white to
ventral margin oftympanum; a black, irregular light brown. Throat and breast usually grayish.
dark spot in the proximal antero-ventral part of The color in life was noted by the collector
upperarmandadjacentpartofchest;asmallarea (ACD) as gray-bro—wn above.
ofareolation on side ofbody posterior to fore- REPRODUCTION. The only female speci-
limb. — men inthecollectionhasmedium-sizedeggsand
DIAGNOSIS. This speciesdiffers from other coiled oviduct. Unfortunately, only one egg is
small-disked species of Philippine Platymantis measurable(ca. 1 mm indiameter). Theeggsare
inthefollowingcombinationofcharacters: very yellow without pigment. It is probable that the
small size, 14.1-15.7 mm SVL for 11 mature species undergoes direct development as is
specimens (10 males and one female; Table 1); known for other species of the genus, i.e., P.
finger disks narrower than those oftoes, about hazelae and P. guentheri (Brown and Alcala
the same width as digits proximal to disks; ter- 1982). —
minal disks bluntly rounded to pointed; dorsum Advertisement Call. The call of this
smooth, and the a—dvertisement call. species sounds like "tet-tet," a chirping sound.
DESCRIPTION. SVL 24.1-15.7 mm for ten The first part ofeach note is between 3800 and
mature males and 15.0 mm for one mature fe- 5500 Hz. The second shorter part is between
male;HL36-40%ofSVL;HW39^14%ofSVL; 4500 and 5500 Hz. The duration ofeach note is
snout rounded; upper jaw slightly protruding; between 0.01 and 0.02 ofasecond. The interval
SnL 14-18% ofSVL; ED 12-15% ofSVL; TD between notes is 0.30 to 0.80 or more seconds
6-10% of SVL; tympanum exposed; usually a (Fig. 1C).
series ofthree whitish tubercles arranged diago-
ALCALA, BROWN AND DIESMOS: PLATYMANTIS 383
Table 1. A comparison ofthesnout-vent length (SVL in mm)oftour
PhilippinespeciesofPlatymantis (N =numberofspecimens).
SVL (Adults)
Species Range Mean
Platymantisdorsalis
Females
Males
PROCEEDINGSOFTHECALIFORNIA ACADEMY OF SCIENCES
384
Volume50, No. 17
o
CD
LU
I
-
CD CD
CD
AONanoayj
(zh>\)
ALCALA, BROWN AND DIESMOS: PLATYMANTIS
385
i
bo
S;
U
m
F
O
(ZH><) A0N3nD3dd
386 PROCEEDINGS OFTHECALIFORNIA ACADEMY OF SCIENCES
Volume50, No. 17
—
advertisementcallofmales. Itisfurtherdifferen- REPRODUCTION. Gravid females were col-
tiatedfromdorsalisby itsshorterSVLandfewer lected in April, May and June, 1995 and 1996.
dorsal ridges and frompygmaeus by its greater Fivefemales had 10-20 (mean 14) large,yellow
SVL (Table 1). In this character, it is in closer unpigmentedeggs,ranginginsizefrom 1.0to2.2
mm
agreement with mimulus. However, it differs indiameter. LikeotherspeciesofPlatyman-
from mimulus in the (1) advertisement call, (2) tis,thisspeciesprobably undergoesdirectdevel-
morereducedwebbingon second and third toes, opment (within the egg capsule) from egg to
and (3) the presence ofnumerous tubercles and froglet. Mt. Banahao had high rainfall
short low ridges on the snout, head, eyelids, (150-500+ mm) during the months of January
dorsum, and hind—limbs. andMaythroughDecember,although itreceived
Description. SVL 20.3-23.9 mm for 18 rain during the other months of the period
mature males and 21.6-28.0 mm for 14 mature 1983-1992 (A. C. Diesmos, unpublished ms.).
females; HL 38^4% of SVL; HW 39^6% of An egg-laying period for this species beginning
SVL; snoutrounded; upperjaw slightly protrud- inAprilorMay isthereforeareasonableassump-
ing; SnL 15-19%ofSVL; ED 12-14%ofSVL; tion. This isstrengthenedbyourobservationson
tympanum exposed,TD7-1 1%ofSVL;canthus other Platymantis species in the Mt. Banahao
rostralis rounded; loresmoderatelyoblique,con- area. Eggs of an arboreal species, probably P.
cave; vomerine teeth strongly protruding, luzonensis,werecollectedonApril 20, 1996and
patches widely separated; fingers not webbed; September 20, 1997. Two of the seven unpig-
fingers with small grooved disks; first, second, mented, whitish oviductal eggs measuring 3.5
mm
and fourth fingers about equal in length, third in diameter were accidentally squeezed out
longer,3FL 13-17%SVL;subarticulartubercles oftheoviductofafemaleP. mimulusonJune22,
oval, large but not pointed; one row ofsupernu- 1996. —
merarytubercleswell developed; innerand mid- Advertisement Call. The male adver-
dle metacarpal tubercles large, oval; outer tisement call ofPlatymantis naomii sounds like
metacarpal tuberclesmall,oval toelongate; hind "psik" repeated at intervals of about 0.6 to 1.1
limbs long,TiL52-61%ofSVL; toeswebbedat seconds forone male(Fig. ID) The frequency is
base: first,second,andthirdtobaseofsubarticu- strongly modulated. The duration of each note
lar tubercle, to distal edge offifth, and short of ranges from about 0.043 to 0.056 seconds. The
basal tubercle on fourth; disks oftoes generally frequencyforeachnoteisabout3160to4520Hz.
larger than those of fingers; subarticular tuber- Thedominant frequency is in thefirsthalfofthe
cles as for fingers; metatarsal tubercles protrud- notes. —
ing: inner elongate, outer round or elongate; ETYMOLOGY. Named after the wife
plantar area smooth; tubercle on heel present; (Naomi)ofthe firstauthor(ACA) in recognition
dorsum, head, eyelids, and limbs with few to ofhersupport for—ourherpetological studies.
numerous tubercles; few to several short, low, Comparisons. This species is about the
irregularly-shaped ridges on posterior head and same size as mimulus, but is much smaller than
anteriordorsum (Fig. 2);throatandchinsmooth; dorsalis and larger than pygmaeus. The foot
belly smoot—h to granular. structure resembles mimulus except for slightly
COLOR. In preservative, the dorsal back- reduced toe webs. The dorsum has a pattern of
ground color is light brown to tannish brown, more numerous tubercl—es (Fig. 2).
darkblotchesintheheadregionandoccasionally EcologicalNote. Thisspeciesoccurson
on sides ofbody; interorbital areaand middle of theforestfloorinthemontaneforestatelevations
back lighter in some individuals; a middorsal of900-2150 m. Its altitudinal distribution does
light line in many individuals; darkcrossbarson notoverlapwiththatofmimulus,which does not
limbs; throat and chest gray or mottled brown, occur above 600 m on the Banahao massif. It is
bellyandhind limbsdirtywhite,sometimeswith themostabundant,ground-dwellingPlatymantis
brown mottling. on Mt. Ban—ahao at 1000 m and above.
In life the background color is light brown RANGE. Found only on Mt. Banahao and
abovewith dark blotchesonanteriorbody, head, Mt. San Cristobal, Luzon Island.
and eyelids.
ALCALA, BROWN AND DIESMOS: PLATYMANT1S 387
Figure2.Platymantisnaomiishowingcolorpatternanddorsal skinornamentationin life.
Discussion mensonwhichthedescriptionofP.pygmaeus is
based; Robert C. Drewes and Jens Vindum for
Thedistinctadvertisementcallshelpediniden- makingavailabletouscomparativespecimens in
tification ofpopulations ofthese two species in the collections ofCAS; AndreaJesse (CAS) for
thefield,aswasthecaseforPlatymantismimulus producing the audio spectrograms, and J. S.
(Brown,AlcalaandDiesmos 1997)andP. bana- Brown forretyping the manuscript.
hao and P. luzonensis (Brown, Alcala, Diesmos
and Alcala 1997). To the human ear the call of Literature Cited
Platymantis dorsalis sounds like "whet-whet'"
(produced by whistling): P. mimulus "osec-sec- Brown,W. C. 1965.NewfrogsofthegenusCornufer
sec"';P.pygmaeus"tet-tet"(achirp);P. naomii (Ranidae)fromtheSolomonIslands.Breviora 1%5
"psik." Frequency modulation is greatest for P. (218):1-16.
naomiiand least forP. dorsalis.
Both ofthese new species belong to the dor- Brown, W. C. and A. C. Alcala. 1982. Modes of
salis Group as delineated by Brown, Brown and reproductionofPhilippineanurans. Pp.416-428in
Advances in Herpetology and Evolutionary Biol-
Alcala (1997b). Based on our current informa-
ogy,R. G. J.andK. Miyata,eds.Mus.Comp.Zool.,
tion these species appearto have very restricted Harvard University.
ranges. Platymantis naomii is known only from
Mt. Banahao, southern Luzon Island and P. Brown, W. C, A. C. Alcala, and A. C. Diesmos.
pygmaeus only from the northern end of the 1997.AnewspeciesofthegenusPlatymantis(Am-
SierraMadre mountains in northeastern Luzon. phibia: Ranidae) from Luzon Island, Philippines.
Proceedingsofthe Biological SocietyofWashing-
ACKNOWLEDGMENTS ton 110(1):18-23.
We are indebted to Danilo S. Balete, Ronald Brown,W. C,A. C.Alcala,A. C.Diesmos,andE.
Alcala. 1997. Species oftheguentheri Group of
Allan Altamirano, Arturo Manamtam, Renato
Platymantis (Amphibia: Ranidae) from the Philip-
Fernandez,GenevieveGee,CristiNozawa,Arne pines, with descriptions offour new species. Pro-
Jensen,FinnDanielsen,andMortenHeegard(all ceedings of the California Academy of Sciences
from the Nordic Agency for Development and 50(1):1-20.
Ecology, NORDECO) for supplying the speci-
.
PROCEEDINGS OFTHECALIFORNIA ACADEMY OF SCIENCES
388
Volume50, No. 17
Brown, W.C, R. M. Brown, and A. C. Alcala. Diesmos, A. C. 1998. The Amphibian Faunas of
1997.'SpeciesofthehazelaeGroupofPlatymantis Mount Banahao, Mount San Cristobal, and Mount
(Amphibia: Ranidae) from the Philippines, with Maquiling, Luzon Island,Philippines. Unpublished
descriptionsoftwonewspecies. Proceedingsofthe MS. Thesis, University of the Philippines, Los
CaliforniaAcademyofSciences49(1 1):405^21 Bafios, Laguna.
CALIFORNIA ACADEMYOF SCIENCES, 1998
Golden Gate Park
San Francisco, California94118