Report on a Rare Developmental Anomaly in the Scorpion, Centruroides vittatus (Buthidae)

3 Pages·1995·2.2 MB·English

by  W David Sissom

,
1995. TheJournal ofArachnology 23:199-201
RESEARCH NOTES
REPORT ON A RARE DEVELOPMENTAL ANOMALY IN
THE SCORPION, CENTRUROIDES VITTATUS (BUTHIDAE)
While perusing scorpion samples to delineate alticola(Pocock), Centruroidesinfamatus(Koch),
the distribution ofCentruroides vittatus (Say) in C. gracilis (Latreille), C. margaritatus (Gervais)
the central United States, we discovered a spec- andC. exilicauda(Wood)(= C. sculpturatusEw-
imen in the collection ofthe Emerson Entomo- ing) (Berland 1913; Brauer 1917; Campos 1918;
logical Museum ofOklahoma State University Franganillo 1934; Millot & Vachon 1949; Va-
with two fully formed metasomas and telsons chon 1953; Williams 1971; Armas 1977). In a
(Figs. 1, 2). This anomaly, involving complete few cases (i. e., in E. germanus, B. leptochelys
duplicationofthemetasomaandtelson,hasbeen and C. gracilis), the duplication involves part of
reportedveryrarelyinthepast.Althoughknown the mesosoma as well, with the bifurcation aris-
in ancient times (see Vachon 1953), it was first ingat the level ofmesosomal segment III orIV.
described in the modem literature by Pavesi Brauer (1917) demonstrated that the condition
(1881) in the chactid, Euscorpius germanus results from splitting ofthe posteriorpart ofthe
(Koch). Duplicate metasomas and telsons have embryonic germ band. In his study of5000 em-
sincebeen reported inE. carpathicus(Linnaeus) bryos ofE. carpathicus, duplication-typeanom-
and in several buthids, including Buthacus lep- alies appeared in 13 specimens; of these, only
tochelys (Hemprich & Ehrenberg), Androctonus one (or0.02%)involvedpotential duplicationof
crassicauda (Olivier), Hottentotta (= Buthotus) the metasoma.
2
1
Figures 1, 2.—Anomalous specimen ofCentruroides vittatus. 1, Dorsal view; 2, Ventral view. Scale line =
10 mm.
199
200 THEJOURNALOFARACHNOLOGY
Figures3,4.—MesosomalsegmentVIIandproximalmetasomalsegmentsofanomalousCentruroidesvittatus.
3, Dorsal view; 4, Ventral view.
The present specimen of C. vittatus an im- metrically placed on the stemite as shown in
,
maturefemale,mostlikelyinthefifthinstar,was Fig. 4.
collected by L. Feldick on 4 November 1988 at We thank D. C. Arnold, curator of the Em-
Kinta,HaskellCounty,Oklahoma.Itisverysim- erson Entomological Museum, Oklahoma State
ilar to the specimens ofA. crassicauda, H. alti- University, for loan of the specimen and our
cola, and C. gracilis illustrated in Millot & Va- wives for assistance with translating the litera-
4)
chon (1949), Vachon (1953), andArmas (1977), ture. ThephotographsweretakenbyD.J. Lyons
respectively. It also generally matches the spec- oftheNCSMExhibitsDepartment;wearegrate-
imen of C. exilicauda described by Williams ful for his efforts.
(1971). Thetwometasomasandtelsonsarefully
LITERATURECITED
formedandthecarinationofthemetasomalseg-
ments is normal. Each metasoma bears an anus Berland,L. 1913. NotesurunScorpionmunidedeux
ventrally at the end of the fifth segment. It is queues. Bull. Soc. Entomol. France, 18:251-252.
quite probable that each metasoma and telson Brauer, A. 1917. Ueber Doppelbildungen des Skor-
was fully functional. pionsEuscorpiuscarpathicusL.Sitz.Ak.Wiss.Ber-
lin, 1917:208-221.
The seventh mesosomal segment is quite ab- Campos, F. 1918. Algunos casos teratologicos ob-
normal, as would be expected in order for it to servados en los Artropodos. Ann. Ent. Soc. Amer-
accommodate two metasomas. The tergite (Fig. ica, 11:97-98.
3) terminates posteriorly in a distinct triangular de Armas, L. F. 1977. Anomalias en algunos Buth-
projection between the origins of the two me- idae(Scorpionida)deCubay Brasil. Poeyana, 176:
tasomas. The lateral keels ofthe tergite are rel- 1-6.
ativelynormal,butthemediankeelisposteriorly Franganillo, P. 1937. Un monstruo aracnologico.
bif.uIrtcsaptoes.tTehreomsetdeimailtemairsgeivnenbemaorsreanabaerrrroawn,td(eFeipg,. MilPMlopet.m,.3J.8S6&o-c4M.3.6CuVIbancahnToorna.iNtaet1.d9e4Hi9s.Zto.o,Olro1dg1ri:e5e5d.(ePs.-SP.corGpriaosnsse.,
concave indentation, and there is an irregularly- ed.), Masson etCie, Paris, 6:1-979.
shaped boss and ridge along the posterior mid-
Pavesi, P. 1881. Toradelfiain uno Scorpione. Rend.
line. This structure is flanked laterally by four Inst. Lombardo, vol. 14.
pairs ofkeels (normal specimens have only four Vachon, M. 1953. The biology of scorpions. En-
keels total - two submedians and two laterals - deavour, 12:80-87.
onthesamestemite).Fivepairsofsetaearesym- Williams, S. C. 1971. Developmental anomalies in
1
RESEARCH NOTES 201
the scorpion Centruroides sculpturatus (Scorpioni- Rowland M. Shelley: North Carolina State
da: Buthidae). Pan Pacific Entomol., 47:76-77. Museum ofNatural Science, P.O. Box 29555,
Raleigh, North Carolina 27626-0555 USA
W. David Sissom: Department of Biology &
WTAMU
Geosciences, Box 808, West Texas Manuscriptreceived15February1995, revised22April
A&MUniversity,Canyon,Texas79016-000 1995.
USA