Growth in the Australian burrowing frog, Cyclorana australis (Gray) (Anura: Leptodactylidae)

2 Pages·1994·0.48 MB·English

by  Steven J Walker

.
Ihin.uiiiion* ofthr f<u\al Soncty of S Au.si. (IW4), 118(2), 147 I4H.
BRIEF COMMUNICATION
GROWTH IN THE AUSTRALIAN BURROWING FROG, CYCLORANA AUSTRAUS (GRAY)
(ANURA: LEPTODACTVL1DAE)
The majority ol known Australian fossil hogs have been a Wild M3dissecting microscope. Ilial length wasexpressed
identifiedbythecharacteristicsofthe ilium,adistinctivebone as the distance between the lip of the dorsal acetabular
in whiihthemorphology vanesgreatly between family,genu*, expansion, and the end ofthe dial shaft1
and species' 1, Hence it is now used extensively as a Thecharacteristicsofthe iliumofthespecimensexamined
diagnostic tool . did nol differ significantly from those described (see Jig,
The physical characteristics ofthe frog can be identified It. The S-V ranged 20.0 mm to 83,1 mm. and IL 6.1 mm to
mm
Iraniihesi/eandpointslormuscularallachmenlontheilium 32,0
These features representadaptationstotheenvironment, For Alinearregressioncomparing,IL withS-Vshowedadirect
example a short dial shaft is characteristic of a burrowing relationship between the body length and the length ofthe
frog which does not make long jumps1 "'*. ilium, i.e. the ilium grows linearly in relation lo the body
Topermitextrapolationofthesizeofa frogfromthelength length throughout ontogeny (see Pig. 2).
ot Ihe dium requires an understanding of ihe relationship The lineargrowth ofC oushntis permits a very accurate
between Ihe ilium length(IDandsnout tovent length (S-V). method for estimating the size of an individual from a
It is generally considered that Ihe dium grows linearly in disarticulated ilium.
relation to the S-V of the donor animal*, I am greatly indebted to Prof. M. J. Tyler lor the
However, thedata fromwhichtheseassumptionsaremade opportunity lo undertake this research and for constructive
have been based on small sample sizes, and little is known criticism oftheearly drafts:, and I am extremely grateful lor
ofCarl) ontogeneticchanges1 . ll isalso important to note (he assislance from K Maurice-Jones in the production ot
that it is common in the Animal Kingdom fora change in the figures.
si/e lo icsull in u change of"the proportions ofthe hotly- A
simpleexampleOfsuchallometriegrowthcanbeseenduring
Ihedevelopment ofhuman beings, in which a large change
in the proportions ofthe limbs and the head, in relation ro
trunk si/e. can be seen when children are compared with
adults*
Thisstudy wasanattempttodeterminethenatureo! growth,
ln»m juvenileloadult form,ot theburrowingfrog Cycforamt i
austndts(Gray. 1842) viatherelationshipbetweenilial length lagtnV - 0_n£>?H+ K372 log1DX
1.90 -
and snout vent length. r*=0.9517.n*24
The ilia examined were dissected from 24 preserved
specimens in the collections held at the Department of
/oology, t niversitv ot Adelaide. Before dissection the S-V
ofeachspecimen wasmeasured withapairofNSKelectronic
digtial callipers The pelvis was then removed, and soaked
inbleachto loosen muscle, beforebeingtransferredtoa V°C
oven to dehvdrale f*»~ 24 hours. The IL, tor each ilium was
measured using electronic digital callipers, with Ihe aid of
Ivlim.t.
0.9 11 1,3 1.5
1-igULI -Lef3t0.l6atemraml.asSpe-cVt-ofKC2v.r1himvmt)t.aaustmlispelvicgirdle logl0 Ilial length (mm)
Abhtevitiihms. D, acel cxp_dorsal acetabularexpansion, Pig. 2. Regression lineofilium lengthofCwlonmouustml'ts
I) pmm,_dorsat prominence; p. prolub. dorsal Willisnout-ventlength For •: = 18-30 mm,y 51.25 mm
protuberance; pre acel. /one pre-acelahular /one. (95% confidence limits =49.36 53*23).
148
Tyler, M. J. (1976) Trans. R. Soc. S. Aust. 100(1), 3-14. 4Trueb, L. (1973) pp. 107-108 In Vial, J. L. (Ed.)
"Evolutionary Biology of the Anurans. Contemporary
2Tyler,M. J. (1982)pp. 159-168InRich, P. V. &Thompson, ResearchonMajorProblems"(UniversityofMissouriPress,
E. M. (Eds) "The Fossil Vertebrate Record ofAustralasia" Columbia).
(Monash Univ. Press, Clayton). 5Tyler, M. J. (1993) Pers. comm.
6Bogin, B. (1988) "Patterns ofhuman growth" (Cambridge
3Tyler, M. J. (1990) Mem. Qld. Mus. 28(2), 779-784. University Press, Cambridge).
STEVEN J. WALKER, 12 Preston St., Blair Athol, S. Aust. 5084