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A case of symmetrical conjoined twins in a bottlenose dolphin Tursiops truncatuo

  • December 2005
Authors:
Erwin J O Kompanje at 1. Erasmus University Rotterdam and 2. Natural History Museum Rotterdam
Erwin J O Kompanje
  • 1. Erasmus University Rotterdam and 2. Natural History Museum Rotterdam
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147
Erwin J.O. Kompanje
Naturalis (Nationaal Natuurhistorisch Museum), Leiden & Natuurhistorisch Museum Rotterdam
Kompanje, E.J.O., 2005 - A case of symmetrical conjoined twins in a bottlenose dolphin Tursiops
truncatus (Mammalia, Cetacea) - DEINSEA 11: 147-150 [ISSN 0923-9308]. Published 29 December
2005
Case reports of conjoined twins (‘Siamese twins’) in wild mammals are very scarce. Most published
reports of conjoined twinning concern cases in man or in domestic mammals. In this article a case of
conjoined twinning in a wild mammal is described: a parapagus dicephalus with unilateral schistopro-
sopus in a bottlenose dolphin Tursiops truncatus stranded on the coast of the Netherlands in 1917. This
case concerns the oldest known case of a symmetrical conjoined twin in a cetacean species.
Correspondence: dr Erwin J.O. Kompanje, Natuurhistorisch Museum Rotterdam, P.O. Box 23452,
3001 KL Rotterdam, The Netherlands, e-mail: e.j.o.kompanje@erasmusmc.nl
Keywords: conjoined twins, parapagus dicephalus, double monster, Tursiops truncatus.
INTRODUCTION
Conjoined twins (‘Siamese twins’) are well
known in man, in domestic and laboratory
mammals, domestic and wild birds and in
wild and captive-bred reptiles, amphibians and
fishes, but are very rarely described in wild
mammals. The precise incidence is unknown,
most likely due to high prenatal and antenatal
mortality. Almost all known cases of con-
joined twins in wild mammals concern unborn
embryos and fetus found during dissection of
the pregnant dead female. The aim of this arti-
cle is to describe a postnatal case of symmetri-
cal conjoined twins in a wild mammal.
Case report
A dead, 125 cm long, newborn female
dicephalic bottlenose dolphin Tursiops trun-
catus (Montagu, 1824), with open umbilicus,
was found on the beach at Wijk aan Zee, the
Netherlands, on 20 July 1917. The specimen
was sold to the Rijksmuseum voor Natuurlijke
Historie (now: Naturalis, National Museum of
Natural History) in Leiden. After preservation,
three photographs were made of the monstrum
(Fig. 1). Shortly afterwards, the specimen
was given on loan to the Anatomical Cabinet
of Leiden University for further study, but
nothing was published on this case. The speci-
men is untraceable now. It is neither in the
Anatomical Cabinet nor in any other museum,
and it is - unfortunately - most probably lost
for science. It supposedly got lost after an
English air raid during the Second World War
(Kompanje 2001). The three photographs
(reproduced here in Figure 1), still present
in the archives of the National Museum of
Natural History, form the only proof of this
rare case. This case was mentioned in a review
of Tursiops strandings along the Dutch coast
(Kompanje 2001).
A case of symmetrical conjoined twins in
a bottlenose dolphin Tursiops truncatus
(Mammalia, Cetacea)
148
 DEINSEA11,2005
Figure1ParapagusdicephalusinabottlenosedolphinTursiops truncatesfromWijkaanZee,theNetherlands,20July1917.
adorsalview,bventralview,cheadsinfrontalview.[ArchivesNaturalis,NationalMuseumofNaturalHistory,Leiden]
ab
c
DISCUSSION
Conjoined twins are always conjoined in one
of only eight sites (Spencer 2001, 2003) and
are named after the site of union [see also
Kompanje (2005) - this volume - for further
details]. Normal twinning is very rare in
cetaceans. González et al. (1999) estimated
a 0.5% occurrence of multiple gestation of
all observed pregnant females in small ceta-
ceans. With the exception of the present case,
and of the case described by Cesarini et al.
(2004), only four cases of conjoined twins in
Cetaceans could be traced in the literature, all
found in unborn foetusses during dissections
in the Japanese and Russian whaling industry
(Table 1). Other complex foetal anomalies
found during these dissections includes holo-
prosencephaly, schistoprosopus and anoto-
cephaly, all in baleen whales (e.g., Zinchenko
& Ivashin 1960).
The present case is the first example of
conjoined twins in a wild newborn dolphin.
A diagnosis of a parapagus dicephalus mono-
somos dibrachius with unilateral schistopro-
sopus on the left head in a full-term female
newborn bottlenose dolphin seems accurate.
A second case in a wild newborn bottlenose
dolphin is described by Cesarini et al. (2004).
Judging from the description these authors
gave (two faces, one braincase, one foramen
magnum) this pair of conjoined twins should
be diagnosed as parapagus diprosopus.
Symmetrical conjoined twins in wild terres-
trial mammals have been very rarely reported
(Table 2). Spontaneous occurrence of con-
joined twins in laboratory animals is uncom-
mon. Szabo (1989) reported one conjoined
twin out of 10.000 in the rat and one case in
4000 rabbits bred in 20 years.
Spencer (2000a, 2000b, 2003) provides con-
vincing evidence that symmetrical conjoined
twins are the result of secondary fusion of two
originally separate monovular embryonic discs,
and are not the result of incomplete fission
producing a partially separated zygote.
149
KOMPANJE:symmetricalconjoinedtwinsinabottlenosedolphin
Reference species taxonomy age
Kawamura 1969 Balaenoptera borealis thoracopagus fetus
Kawamura & Kashita 1971 Stenella coeruleoalba cephalopagus fetus
Kamiya et al. 1981 Stenella coeruleoalba parapagus dicephalus fetus
Zinchenko & Ivashin 1987 Balaenoptera acutorostrata thoracopagus fetus
Kompanje 2001 Tursiops truncatus parapagus dicephalus newborn
Cesarini et al. 2004 Tursiops truncatus parapagus diprosopus newborn
Table1PublishedcasesofsymmetricalconjoinedtwinsinCetacea.
Reference species taxonomy age
Reisel 1671 Lepus europaeus cephalopagus newborn
Jung 1671 Lepus europaeus cephalopagus newborn
Seger 1671 Lepus europaeus cephalopagus newborn
Mentzel 1686 Alces alces cephalopagus fetus
Neugebauer 1851 Lepus europaeus cephalopagus newborn
Benesch 1957 Lepus europaeus cephalopagus newborn
Fay 1960 Odocoileus virginianus parapagus dicephalus fetus
Table2Publishedcasesofsymmetricalconjoinedtwinsinwildmammals,otherthanCetacea.
150
 DEINSEA11,2005
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Jung, G.S., 1671 - Monstrum Leporinum - Miscellanea
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Received12October2005
Accepted9November2005
DEINSEA - ANNUAL OF THE NATURAL HISTORY MUSEUM ROTTERDAM
P.O.Box 23452, NL-3001 KL Rotterdam The Netherlands
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... Some share one umbilical cord, other types, like the thoracopagus, have two umbilical cords. Stenella coeruleoalba cephalopagus fetuses Kamiya et al. 1981 Stenella coeruleoalba parapagus dicephalus fetuses Zinchenko & Ivashin 1987 Balaenoptera acutorostrata thoracopagus fetuses Kompanje 2001Kompanje & 2005b Tursiops truncatus parapagus dicephalus neonates Dabin et al. 2004 Tursiops truncatus parapagus diprosopus neonates Aytemiz et al. 2014 Tursiops truncatus parapagus dicephalus neonates Tamburin et al. 2014 Eschrichtius robustus thoracopagus neonates this contribution ...
... The symmetrical conjoined twin harbour porpoises described here can be determined as parapagus dicephalus. Three other cases of parapagus dicephalus are known in cetacean species, one in Stenella coeruleoalba (Kamiya et al. 1981) and two in Tursiops truncatus (Kompanje 2001(Kompanje , 2005bAytemiz et al. 2014). ...
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Siamese Twins in the Sei Whale Balaenoptera borealis Lesson
Article
  • Feb 1969
ALTHOUGH there have been comprehensive biological studies of whales since 1925 when the Discovery Committee founded the research station at South Georgia, there have been no reports of Siamese twins in whales as far as I know. I now report briefly the results of morphological observations on sei whale Siamese twins found on the Japanese whaling factory ship Nisshin Maru (Taiyo Fisheries Co.) in the Antarctic whaling season 1967–68.
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Theoretical and analytical embryology of conjoined twins: Part I: Embryogenesis
Article
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Theoretical and analytical embryology of conjoined twins: Part II: Adjustments to union
Article
A previous report in this journal (Spencer, 2000) discussed the probable embryologic etiology of conjoined twins, along with a system of classification based on the embryological structures postulated to be involved in the union. Part II correlates and compares the variations in the abnormal development of the individual organ systems in more than 1,200 actual cases, revealing details of embryogenesis not considered in previous publications. The site, incidence, and range of anomalies in the conjoined structures, as well as the associated malformations, follow a definite pattern as the union proceeds from one area to another; many can be explained in relation to the proposed embryologic adjustments to union, including both temporal and spatial influences. In addition, six currently inexplicable or unclassifiable cases are briefly described (including one with 12 feet), as well as two examples of early abnormal conjoined twins. Clin. Anat. 13:97–120, 2000. © 2000 Wiley-Liss, Inc.
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Parasitic conjoined twins: External, internal (fetuses in fetu and teratomas), and detached (acardiacs)
Article
  • Nov 2001
During the course of researching the embryologic etiology of conjoined twins, more than 1260 individual cases were collected from the literature and the reported abnormal anatomy tabulated and evaluated in the light of known embryology. It soon became apparent that the association of conjoined twins and their parasites with fetuses in fetu, acardiacs, and teratomas was more frequent than could be attributed to chance. These anomalous fetuses form a continuum, strongly suggesting that they are all variations of abnormal conjoined twinning, with the site of union and the extent of damage (or defect) of one embryo resulting in (1) an externally attached parasitic twin, (2) an enclosed fetus in fetu, (3) an internal teratoma, or (4) an acardiac connected via the placenta. Common patterns among them are a family history of twinning, the predominance of females, and the frequent presence of a twin or triplet accompanying the malformation. The several reports of chromosomal abnormality suggest that perhaps, at least on occasion, it is a genetically imperfect embryo that develops into a defective fetus. Of singular importance is the fact that rarely, if ever, is either a functional heart or a competent brain found in any of these abnormal fetuses, suggesting that the etiology of all of them is a primary cardiac malformation with secondary disruption in the development of the brain.
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1957 -Lehrbuch der tierärztlichen Geburtshilfe und Gynäkologie -Urban und Schwarzenberg
  • F Benesch
Benesch, F.,1957 -Lehrbuch der tierärztlichen Geburtshilfe und Gynäkologie -Urban und Schwarzenberg, München, Germany