Maslin, T. Paul

Walker, J. Martin

Archivsystem Ask23

Chemidophorus tigris punctatus : A new whiptailed lizard from Northwestern Sonora, Mexico.

CU Scholar Institutional Repository

U N I V E R S I T Y  OF C O L O R A D O  S T U D I E SS e r ie s  in  B i o l o g y  No. 20U n i v e r s i t y  o f  C o l o r a d o  P r f .s s  B o u l d e r ,  C o i .o r a d o  August, 19f>5CNEMIDOPHORUS TIGRIS PUNCTATUS: A NEW WHIPTAILED LIZARD FROM NORTHWESTERN SONORA, MEXICOJ. M a r t i n  W a l k e r  a n d  T. P a u l  M a s l i n *T h e  w h ip tailed  lizard C nem idophorus  tigris tigris ranges through a large portion  of the in terio r of Southw estern N orth  A m erica and w ith in  this area exh ib its  consid erable variation . S tebb in s (1 9 5 4 ), for instance, reported  that this form  is probably  a com posite of m ore than one subspecies as, “P op u lations of the C olorado D esert differ from  those of the M ojave D esert and regions to the n o rth .” From  M arch  1963 to M arch 1965, the U niversity  o f C olorad o M useum  secured a large nu m ber of specim ens of a d istinctive v arian t o f Cncrnidophorus tigris from  the vicin ity  of P uerto  Penasco, Sonora, M exico. T h ese  specim ens, along w ith  a large series from  the C arnegie M useum , are readily  d istinguished from  m ore northerly  popu­latio n s of C n em id o p ho ru s  tigris tigris in  possessing a dorsal p attern  con­sisting o f a gray dorsum  w ith  sm all b lack  and large w hite spots. In  a llu ­sion to this spotted p attern  of adidts, and usually juveniles, we designate this form  as:^ D ep artm ent o f /oology, U n iversity  o f Arkansas, Fayetteville , and U n iversity  o f C olo­rado M useum , B o u ld er , respectively.F ig u r e  1. Left to right: ventral, dorsal, and lateral views of the holotype (UCM  29200) of C nem idophorus ligris punctatus.C.nemidophorus ligris punctatus  subsp. nov.D esert Spotted  W h ip ta il (F igure 1)H o lo ly p e :  U niversity  of C olorado M useum  29200 (form erly C. J. M cCoy, J r .  field n u m ber 5 7 9 5 ) , collected  by C. J .  M cCoy, Jr ., from  C h olla  Bay, ca. 1 m iles northw est P u erto  Penasco, Sonora, M exico , on A p ril 1, 1965.Topoparatypes:  U niversity  of C olorado M useum  29198-29199, 29201- 29217 and C arnegie M useum  40310-40356.Paralypes:  U niversity  o f C olorado M useum  13205 from  E l P uerto , 13206 from  21 m iles E  San L uis, 19245-19247 from  30.6 m iles SW  Sonoyta, 19107- 19113, 20504  from  P u erto  Penasco, 29218-29220 from  5 m iles W  P uerto  Penasco. C arnegie M useum  40214-40219 from  15.5 m iles N E  P u erto  Penasco, 40426-40429 from  P elican  P o in t 8 m iles N W  P u erto  Penasco (all paratypes from  Sonora, M exico) .Diagnosis:  A  subspecies o f C nem idophorus tigris d istinguished from  other form s by a com bin ation  of the fo llow ing characters: (1) ligh t gray dorsal ground color, (2) fou r dorsal stripes of ju ven iles replaced  by a lin ear p at­tern  of b lack  and w hite spots early in  ontogeny (3) dorsal p attern  of adults consisting o f sm all b lack  and w hite spots m id-dorsally and sm all b lack  and large w hite spots on the flanks; (4) head light brow n or grayish-brown dorsally and spotted w ith b lack  la tera lly ; (5) ch in  gray or w hite w ith  a p ink suffusion and usually m in u te  b lack  spots; (6) chest scales light gray or w hite often  narrow ly edged w ith b lack ; (7) belly  scales com pletely w hite or w ith a very narrow  b lack  an terior edge, never checkered; (8) ventral surface of the ta il w hite; (9) about 75 granules around m idbody; (10) ab ou t 167 granules from  the in terp arieta l scale to the base o f the ta il; (11) and about 41 fem oral pores.Description of the holotype:  T h e  holotype is a m ale (U C M  29200) w ith a p erfect ta il and a snout to vent length  of 82 mm . Features of scutellation  are: 2 fro n top arie ta ls ; 3 parietals; 4-4 supraoculars; 5-5 supralabials; 15-15 la tera l supraocu lar granules; the supraorb ital sem icircles extend  anteriorly  to the m id dle of the th ird  supraoculars; sm all scales at the edge of the gu lar fo ld  (m esoptycliials) ; g ranu lar postantebrachials; 71 granules around m idbody; 154 granules from  the in terp arieta l scale to the base of the tail; 22-23 fem oral pores; and 34-35 subdigital lam ellae on the longest toes of the pes.Features o f the co lor p attern  are: head grayish-brow n dorsally, black- spotted la tera lly ; dorsum  light gray w ith n ine lin ear series of b lack  spots betw een w hich are eleven lin ear series of w hite spots; h in d  lim bs gray w ith sm all b lack  and large w hite spots; chin gray (suffused w ith p in k  in  life) w ith m in u te  b lack  spots; chest grayish w ith some scales edged w ith  b lack ; belly w hite; and ventral surface of the ta il white.V A R IA T IO NSize: A vailable lo r study are 93 specim ens of w hich 44 are fem ales and 49 are m ales. T h e  largest specim en is a m ale w ith  a snout to vent length  (SV L) o f 93 mm . T h e  largest fem ale has a SV L  o f 88 m m ., and the sm allest in ­dividual is a m ale w ith  a SV L  of 49 mm . T h e  SV L  frequencies of ou r series are depicted in rI ’ab le I.Color paltern :  Juveniles of C nem idophorus tigris punctatus  (SV Ls of ca. 49 m m . to ca. 70 m m .) m ay have fou r dorsal stripes w hich are only a litt le  lig h ter than  the grayish ground color o f the dorsum . T h e re  is a p air of paravertebrals w hich orig inate near the posterior edge of the parietals and term inate at the base of the ta il, and a p air of d orsolaterals w hich orig inate near the superciliaries and term inate n ear the base o f the tail. In  some ju ven iles o f punctatus,  how ever, the stripes have been  disrupted by the en ­croachm ent o f pigm ents from  the in terven in g  spaces. A ll ju ven iles avail­able to us have large w hite spots along the flanks (som etim es vertica l w hite bars are present) and on the sides of the head. T h e  ventral p attern  consists o f a w hite ch in  w ith fa in t gray m arb ling , a w hite chest, and a w hite belly w ith  a grayish or b lack ish  suffusion on the ou ter edges of the la tera l belly  scales.L arger individuals of punctatus  (SV Ls of ca. 71 mm . to ca. 80 m m .) have a ligh t gray dorsum  (usually w ith litt le  if  any evidence of the dorsal stripes), lin ear series of sm all b lack  and w hite spots are present in the m id-dorsal region, sm all dark and larger w hite spots along the flanks and on the dorsal surface o f the h ind  legs, a gray or w hite ch in  w ith  a suffusion of p in k  and, often , sm all b lack  spots, a w hile or lig ht gray chest, a w hite belly  w ith  some o f the scales edged anteriorly  w ith b lackish  pigm ents, and a ta il w hich is pred om inantly  w hite ventrally.T h e  largest specim ens of punctatus  available to us (SVLs of ca. 81 mm . to 93 m m .) show the fo llow ing variations in  the dorsal p attern —mid-dorsal region is gray w ith n o  spots, w ith  scattered spots, or w ith a lin ear series of spots. Seldom  is there any evidence o f the dorsal stripes in  specim ens of this size class. T h e  flanks m ay have sm all b lack  and/or large w hite spots or have scattered and irregularly  disposed b lack  spots. T h e  head is heavily m ottled  and spotted w ith b lack  laterally . T h e  ch in  m ay be e ith er gray or w hite w ith a p ink  suffusion and may or m ay n o t have m inute b lack  spots. T h e  chest scales may be pred om inantly  gray or wrh ite  w ith narrow  b lack edges and the belly  is usually w hite, althou gh  occasionally  very lig h t gray, never achieving the checkered appearance of C. tigris tigris from  N evada, U tah , and C aliforn ia . T h e  dorsal surface of the ta il is usually yellow ish brow n w ith  m in u te  black spots proxim ally , blackish-brow n distally, and w hite beneath .In  sum mary, the m etam orphosis o f color p attern  in  both sexes of19 53 55 56 GO 6-1 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 91 92 93 i I 3 1 1 1 1 1 2  4 1 2  1 3  ~3 7 2 2 3 3 3 1 Vc 1 2  2 1 2 2 1 1 4 5 2 6 2 4 3 2 2  2C nem idophorus tigris punctalus  involves fo u r basic steps: (1) the dis­ru p tion  of the stripes by the encroachm ent o f p igm ent from  the in terven in g  spaces, (2) the appearance of b lack  spots on the dorsum , (3) the appear­ance of gray, p ink, and often  b lack  p igm ent on  the ch in , and (4) the ap­pearance of b lack ish  p igm ent on the an terio r edges of the chest scales.T h e  p arallel developm ent of color p attern  in  b o th  sexes results in  no apparent sexual d im orphism  in adults.Sculellation:  D ata  for C n em idophorus  tigris punctalus  are: 66-93 (75.4 ±  S.E. 0.7, N  =  64) granules around m idbody, 150-179 (163.6 ±  1.8, N =  25) granules from  the in terp arieta l scale to  the base of the ta il, 34-50 (42 ±  0.4, N  =  61) com bined  fem oral pores on b o th  h ind  legs, 29-39 (33.3 ±  0.3, N =  46) subdigital lam ellae on the longest toe o f the left pes. T y p ica l o f a ll m em bers o f the tigris com plex, punctatus  has sm all scales at the edge o f the gular fo ld  (m esop tych ia ls), g ran u lar postante- brachials, and the usual n u m ber of 2 fro n top arieta ls, 3 parietals, and 4-4 supraoculars. C onsiderable variation  is evident in  the an terio r extension  of the supraorb ital sem icircles. T h ir ty  specim ens have sem icircle series w hich extend  to the m iddle of the third  supraoculars, 16 to the posterior edge of the fro n ta l, 10 to  the second su p raorb ita l sutures, 3 to the m iddle of the second supraoculars, and 4 have a com plete series. D efin itions of the above characters o f scutellation  may be found  in D u ellm an  and Zweifel (1 9 6 2 ).C O M P A R IS O N ST o  the northeast, east, and south of C n em id o p ho ru s  tigris punctatus  is found C. tigris gracilis  and to the n orth , northw est, and west is found  the nom inal subspecies C. tigris tigris. N o character or com bin ation  of char­acters of scutellation  serves to distinguish these three form s; only co lor and p attern  serve as im p ortan t diagnostic features.P attern  characteristics of gracilis w hich distinguish it from  punctatus  are: (1) ju veniles have six dorsal stripes w hich are often  evident in adults, (2) the chin , chest, and belly  of adults are b lack, (3) gracilis has a ventral b lack  ta il band  two scales wide.C nem idophorus tigris punctatus  appears to be m ost closely re lated  to C. tigris tigris b u t this form  is readily  d istinguished from  punctatus  by the follow ing characteristics: (1) adults re ta in  fou r clearly  defined light dorsal stripes separated by b lack  interspaces, (2) p ostaxillary  region and p art of llank extensively suffused w ith  b lack ish  pigm ent, (3) fore lim bs boldly m arbled  w ith b lack , (4) b lackish  p igm ent o f the flanks in teru p ted  byw hite vertical bars, (5) belly  and chest extensively checkered with black pigm ent, (6) ta il has a ventral b lack  band  two scales wide.R A N G EAs now  understood, the range o f C n em idophorus  tigris punctatus  en- com pases a sm all region o f the Sonoran  D esert in  northw estern Sonora, M exico , from  the vicin ity  o f P u erto  Penasco on the coast, in land  to the northeast to at least 30.6 m iles south southwest of Sonoyta and northw est to the vicin ity  o f the C olorado R iv er and San L uis, Sonora. F ou r specimens from  Y um a C ounty, A rizona have the b lackish  ventral suffusion of gracilis and U C M  specim ens from  San B ern ard in o  County, C aliforn ia  are referrab le  to the n om in al subspecies. T h u s  we assume th at b o th  of these form s are replaced  by punctatus  in  northw estern Sonora a short d istance south of the in tern a tio n a l border.R E M A R K ST h e  re latio n sh ip  betw een the form s now allocated  to C nem idophorus  tigris, and am ong its close relatives on the islands in  the G u lf o f C aliforn ia , represent one of the m ost com plex problem s in  the genus C nemidophorus.  O f special in terest are the zones of contact betw een m ainland  subspecies. T h e se  zones, from  all available  evidence, are very narrow  w ith an abrupt rep lacem ent o f one form  by another. In  one such zone along the Arizona- New M exico  border, Zw eifel (1 9 6 2 ) , found  n o t only in term ed iate individ ­uals betw een C. tigris gracilis  and C. tigris marmoratus,  b u t also both paren tal types. In  some ways the p op u lation  of such zones resem ble hybrid swarms ra th er than typical subspecific intergradations. T h is  in terp reta ­tion  is in  keeping w ith  the e lectro p h oretic  plasm a protein  patterns studied by D essauer, F ox , and Pough (1962) of the same population  studied m orphologically  by Zw eifel (1 9 6 2 ). T h ese  studies serve to illu strate  that the subspecies o f C n em id o ph o ru s  tigris do n ot represent an array of forms sm oothly intergracling w ith  each other through a series of step clines, but ra th er a n u m ber of d istinct fa irly  hom ogenous variants each representing the p h en etic  expression o f an adaptive peak. Such p op u lation  patterns fu rth er suggest th at each of these form s has been isolated from  the others for some tim e and in  those instances where contact betw een races is know n to occu r it  appears th at this contact has only recently  been reestablished.T h e  reco g n itio n  o f punctatus  brings the num ber of subspecies of tigris to 14. T h e re  are, how ever, a nu m ber of distinctive insu lar races w hich also should be recognized or revived. W h ile  these form s obviously cannot in te r­breed, they, nevertheless, dem onstrate the ease w ith w hich d istinctive races can evolve w ith in  th is w idespread and adaptable species.A C K N O W L E D G M E N T SF ield  work fo r this study was in p art supported by N atio n al Science F ou nd ation  G ran t G B  1813 to T .  P au l M aslin . W e are also indebted  to Drs. N eil D. R ich m on d  and C. J .  M cCoy, J r .  for perm ission to exam ine the Carnegie M useum  specim ens in  th e ir care.L I T E R A T U R E  C IT E DD f .s s a u e r ,  H . C., W . F o x ,  and F .  H . P o u c h .  1962. Starch-gel electrophoresis of transferrins, esterases and other plasm a proteins of hybrids betw een two subspecies o f w h iptail lizard (genus C n em id op h o ru s ) .  C opeia 1962: 767-774.D u f . l l m a n ,  W . E ., and R . G . Z w e i f e l .  1962. A synopsis o f lizards o f the sexlineatus  group (genus C nem ido p h orus ) . B u ll. Am . M us. N at. H ist. 123:155-210.S t e h b i n s ,  R . C. 1954. A m phibians and reptiles of western N orth  A m erica.M cG raw -H ill B o o k  Co. In c., New Y ork, x x ii +  528 pp.Z w e i f e l ,  R . G. 1962. Analysis o f hybrid ization  betw een two subspecies of the desert w h iptail lizard, C nem idophorus  iigris. C opeia 1962: 749-766.

Undetermined

Cnemidophorus tigris punctatus: A new whiptailed lizard from northwestern Sonora, Mexico

Walker, James Martin

T. Paul Maslin

Red Mexicana de Repositorios Institucionales

Cnemidophorus tigris punctatus: a new whiptailed lizard from northwestern Sonora, Mexico

https://scholar.colorado.edu/downloads/9593tv75c

Cnemidophorus tigris punctatus: A new whiptailed lizard from northwestern Sonora, Mexico

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