Table Of ContentCicat Masiii NatmalisI 57(1), i') 1997, pp.3(i3-;3fi5
REPRODUCTION IN THE WESTERN CORAL SNAKE,
MICIU'ROIDES EUnYXANTIIHS (ELAPIIME),
FROM ARIZONA AND SONORA, MEXICO
Stephen H. (ioldhcr^'
Keyuonlft:npnxliiclioit, MicniroidcstMiiyxantliiis,ucslcni((inilsnake.Arizona, Mexico.
The western eoral .snake, Micniroidcs cunj- cut into sections at 5 |im. Slides were stained
xantluis (Keiiiiieott, hSfiO), ranj^es fVom eeiitial with Harris' hematoxylin followed by eosin
Arizona and southwestern New Mexieo to counterstain. Testes slides were examined to
southern Sinaloa, Mexieo, and occurs from sea determine the stage of the male cycle; epi-
level to 1770 ni (Stehhins 1985). Information didymides and vasa deferentia were examined
on the hk)\oji,y ofthis species is in Hoze (1974). for .sperm. Slides of kidney sexual segments
There are only anecdotal accounts of repro- were examined for secretory activity. Ovary
duction in M. euryxanthtis (Funk 1964, Behler slides were examined for the presence ofyolk
and King 1979, Stehhins 1985, Ernst 1992, deposition.
Williamson et al. 1994, Kossi and Rossi 1995, Data on the male Micruroides euryxanthus
Degenhardt et al. 1996). According to Lowe testicular cycle are presented in Table 1. Tes-
et al. (1986), the M. euryxanthus reproductive ticular histology was similar to that reported
cycle is tied to summer rains; egglaying occurs by C;()ldberg and Parker (1975) for the colu-
in July-August with hatchlings appearing in brid snakes Mastico])his taeniatus and Pituophis
summer. Shaw (1971) assumed breeding tnelanoleiicus. In the regressed testes seminif-
occurred in the spring, with egg deposition in erous tubules contained spermatogonia and
late spring or early summer. Roze (1996) re- Sertoli cells. In recrudescence there was re-
ported that in Sonora, Mexico, oviductal eggs newal ofspermatogenic cells characterized by
were found in M. euryxanthus in the 2nd half spermatogonial divisions; primary and sec-
of May and the end of July; egg laying ondary spermatocytes and spermatids mayhave
stretched from the end ofJuly to September. been present. In spermiogenesis metamor-
The purpose ofthis report is to provide infor- phosing spermatids and mature sperm were
mation on reproduction in M. euryxanthus. present. Males undergoing spermiogenesis
I report on data from 56 Micruroides eury- were found in all months examined (April-
xanthus (35 males, mean snout-vent length November; Table 1). Epididymides and vasa
[SVL] = 382 mm ± 41.9.s, range 320-493 mm; deferentia of spermiogenic males contained
21 females, mean SVL = 371 mm ± 49.7 s, sperm. The smallest spermiogenic male mea-
range 315-497 mm) from Arizona and Sonora, sured 320 mm SVL. Only 2 males with re-
Mexico, in the herpetology collections of the gressed testes were found, 1 each in June (493
University ofArizona (UAZ), Tucson, and the mm SVL) andAugust (330 mm SVL). No males
NatiHiil History Museum ofLosAngeles County with recrudescent testes were noted. The sex-
(LACM), Los Angeles (Appendix). Counts were ual segment of the kidney was enlarged and
made of oviductal eggs or enlarged follicles contained densely staining secretory granules
mm
(>3 diameter). The left testis, epididymis, in spermiogenic males. Mating coincides with
and vas deferens and part of the kidney were hypertrophvofthe kidneysexual segment (Saint
removed from males; the left ovary was re- Girons 1982).
moved from females for histological examina- The smallest reproductively active female
tion. Tissues were embedded in paraffin and (enlarging eggs) measured 356 mm SVL. To
'DepartiiientofBitiloKy,WliittierColleKe,Whittier,CA90608.
363
Great Basin Naturalist [Volume 57
364
Table 1. Monthly distribution ofconditions in seasonal
testicularcycle o\'Micniroide.s curyxantlm.s. Values shown
are the nimibers ofmales with testes exhibiting each of
the2conditions;nonewereinrecrudescence.
Month
1997] Notes 365
W
1996. Ri'iirodiiction in tlu'sadcUed li-afhoscsnake, ico. Pages 157-172 in Biicherl and E.E. Buckley,
.
Pliyllorhyiicluis hnncni and the spotted leafnose editors.Venomousanimalsand theirvenoms.Volume
snake,Phyll<)rhyiicliii.sdccw'tatu,s, fromArizona.Jonr- II.Venomousvertebrates.Academic Press, NY.
nalofIlerpetologN'30:280-282. SIKBBINS, R.C. 1985. Afieldguidetowesternreptilesand
1997. Reproduction in the western sho\ehu)se amphibians. Hougliton-Mifflin, Boston.336pp.
sn.ake, Chionactisoccipitalis (Colubridae), from CaH- Williamson, M.A., PW Hvder, and J.S. AppLEf:ARTH.
fornia.GreatBasin Naturahst57:85-87. 1994. Suiikes,lizards,turtles,frogs,toadsandsalaman-
Goldberg, S.R.,ani:)W.S. Pakkek. 1975. Seasonal testicu- ders ofNewMexico. Sunstone Press, SantaFe, NM.
larhistology'ofthecoluhrid snakes,Masticophis tac- 176pp.
niatitsandPifuophismelanoleiicus. Heipetologica31:
317-322. Received15February1997
Lowe, G.H., C.R. Schvvalhe, and T.B. Johnson. 1986. Accepted2Apiil1997
The venomous reptiles ofArizona. Arizona Game
andFish Department, Phoeni.K. 115pp.
QuiNN, H.R. 1979. Reproduction and growth oftheTexas
coral snake {Micninisfiilviiis tenerc). Copeia 1979:
453-463.
Rossi,J.V,andR. Rossi. 1995. SnakesofdieUnitedStates Appendix
and Canada. Keeping them healthy in captivity. Vol-
ume 2. Western area. Krieger Publishing Company, Specimens examined from herpetology collections at
Malabar, FL.325pp. the Natural History Museum of Los Angeles County
RoZE,J.A. 1974.Micniroides SchmidtWesterncoral snake. (LACM) and the University ofArizona (UAZ). Sonora,
Catalogue of American Amphibians and Reptiles Mexico: LACM 16056, 104325. UAZ9358, 27079, 35214,
163.1-163.4. 44875-76, 45202-203, 45904. Arizona, Cochise: UAZ
1996. CoralsnakesoftheAmericas:biology,iden- 14435, 14616, 39679, 39681, 45843, 46378, 46834, 50046.
tif.ication,andvenoms. KriegerPublishingCompany, Gila: 43287. Pima: UAZ 9360, 14429-31, 14433, 14436,
Malabar, FL.328pp. 14438-39, 14441-42, 14445-46, 14451, 14618-19, 27075,
SaintGirons,H. 1982. Reproductivecyclesofmalesnakes 29658, 34459, 35829, 36557, 37831, 40874, 42608, 45011,
andtheirrelationshipswithclimateandfemalerepro- 46420, 47344, 47432, 47484, 48342, 48784. Pinal: UAZ
ductivecycles. Heipetologica38:5-16. 14432, 14434, 14444. Santa Cruz: UAZ 39677. Yavapai:
Shaw, C.E. 1971. The coral snakes, generaMicrurus and UAZ14443,39669,45748.
Micniroides,oftheUnited Statesandnorthern Mex-
