An anguilline Norwegian sea
serpent (sea-orm) depicted on Swedish cleric Olaus Magnus's famous antiquarian
maritime map of 1539, the Carta Marina
One of cryptozoology's most enigmatic
episodes is undoubtedly the very curious (and confusing) case of the bottled
sea serpent.
This had attracted particular attention in
1965, when sea monsters enjoyed a renaissance in scientific respectability -
thanks to the publication that year of a now-classic tome by cryptozoologist Dr
Bernard Heuvelmans, entitled Le Grand Serpent-de-Mer (a somewhat
different English version, In the Wake of the Sea-Serpents, appeared in
1968, also incorporating a greatly condensed version of another of his books,
dealing with the giant squid and alleged giant octopuses).
First edition of Le Grand
Serpent-de-Mer (© Dr Bernard Heuvelmans/Plon Publishing)
Within his book, Heuvelmans proffered
evidence for believing that 'the great sea serpent', one of cryptozoology's
most celebrated creatures, might actually be a non-existent composite - i.e. it
had been 'created' via the erroneous lumping together (by previous
investigators) of eyewitness reports that in reality feature a number of totally
different types of animal.
In short, there was no single,
morphologically heterogeneous species wholly responsible for all sea
serpent reports on record. Instead, there were several well-defined,
separate species collectively responsible for those reports.
Heuvelmans's 'super eel'
category of sea serpent (© Tim Morris)
Some of them, according to Heuvelmans, were
species still unknown to science, and included various unusual seals and whales,
a giant turtle, a marine crocodile-like reptile, and a giant-sized 'super eel'.
If his hypothesis was correct, this would have profound ichthyological
implications.
For as a result of a chance discovery made
over 30 years earlier, it meant that at least one bona fide sea serpent had
already been captured - a sea serpent whose remains, moreover, were preserved,
bottled, and available for scientific scrutiny!
Common European eel Anguilla anguilla, 1837 painting
On 31 January 1930, the Danish research
vessel Dana unexpectedly captured an exceptionally long eel larva
(leptocephalus) at a depth of about 900 ft,
west of the Agulhas Bank and south of the Cape
of Good
Hope,
South Africa.
Whereas leptocephali of the common European eel Anguilla anguilla
measure a mere 3
in long at most, and even those of the
formidable conger eel Conger conger only reach 4 in, the Dana's
remarkable specimen was a colossal 6
ft 1.5 in!
This in itself was quite staggering, but its implications were even more
astounding.
The Dana giant
leptocephalus as a preserved, bottled specimen (© Prof. Jørgen Nielsen/Zoological Museum of
Copenhagen/courtesy of Lars Thomas)
During their metamorphosis from
leptocephalus to adult, true eels (anguillids) greatly increase their total
length - the precise index of growth varying between species. In the common
eel, the increase is generally eighteen-fold, producing adults measuring around
4.5 ft;
in the conger, it can be as much as thirty-fold, yielding adults up to 10 ft.
19th-Century
engraving of a conger eel
Consequently, as conceded by Dana ichthyologist
Dr Anton Bruun, in the case of the Dana leptocephalus, which was already
6 ft
long, there existed the incredible possibility that this would have
metamorphosed into a monstrous adult measuring anything between 108-180 ft,
with a length of 50
ft seemingly the very minimum (less
than a nine-fold increase) that even the most prudent estimator might expect of
such a larva! Needless to say, any species of eel attaining such stupendous lengths
as these would make an excellent candidate for those sea serpents grouped
within Heuvelmans's 'super eel' category.
Artistic representation of an
adult super eel's possible appearance in life (© Thomas Finley)
After its capture, the Dana leptocephalus
was preserved in alcohol and has since resided in a specimen bottle within the
collections of Copenhagen
University's
Zoological
Museum. Periodically, it has been taken out of its
bottle to be examined, and as a result it has gradually shrunk, but it remained
a notable riddle in need of an answer – especially when, as the years
progressed, a few other inordinately long leptocephali were obtained.
In 1959, an anatomically similar but
somewhat shorter specimen, collected on 16 July 1958 in
shallow water at Westland, South Island, New Zealand, was described by ichthyologist Peter Castle as a new species, which he formally dubbed Leptocephalus
giganteus – and to which the Dana specimen was later assigned.
The holotype (type specimen) of Leptocephalus giganteus - full provenance details given above (© Museum of New Zealand Te Papa Tongarewa (P.002603)/Creative Commons BY-NC-ND licence)
Interestingly, the Danish research vessel Galathea supposedly obtained a
6 ft
leptocephalus during its voyages in the early 1950s, but no formal record of
this (let alone the specimen itself) appears to exist. Even so, two specimens of L. giganteus
certainly did exist, and the reality of the infamously elusive sea serpent, or
at least one of its constituent members, seemed at last to have been fully
endorsed. Inevitably, however, the truth proved very different.
In 1966, two
much smaller specimens of L. giganteus were documented. Measuring just
under 4 in
and 11 in
respectively, they had been sifted from the stomach contents of an Alepisaurus
lancet fish captured in the western Atlantic.
Except for their modest lengths, they corresponded very closely to the New
Zealand example, and were
carefully studied by Miami
University
ichthyologist Dr David G. Smith, in a bid to pinpoint conclusively the
taxonomic affinities of L. giganteus in relation to the many other
species of eel known to science.
An adult specimen of the
snubnosed spiny eel Notacanthus chemnitzii, a typical notacanthid
(public domain)
In March 1970, he exploded the sea serpent
scenario for L. giganteus - by announcing that its two smaller specimens
were the larvae of a notacanthid (spiny eel), not of an anguillid (true
eel). This spelled doom for their species' claim to fame as (in its adult
phase) a genuine sea serpent - because in stark contrast to the leptocephali of
true eels, those of notacanthids do not greatly increase their length
during metamorphosis from larva to adult.
Consequently, predictions that mature
specimens of L. giganteus would measure over 100 ft
were totally unfounded. Instead, when the unknown adult phase of this species
was finally collected, it would be very little longer than the leptocephalus,
i.e. a mere 6
ft or so.
An adult specimen of the froghead
worm eel Coloconger raniceps, a typical short-tailed eel or colocongrid (public
domain)
More recently, however, this
reclassification of L. giganteus as a notacanthid has itself been
challenged, so that nowadays it is popularly classed instead as a species of
short-tailed eel (aka worm eel or colocongrid), within the family Colocongridae,
housed in turn within Anguilliformes, the order of true eels. Accordingly, it has been renamed Coloconger giganteus (although some researchers
still deem it to be a notacanthid).
In any event, just like the notacanthids, the
short-tailed eels do not display a sizeable increase of length during
larva-to-adult transformation. So the identification of C. (or L.)
giganteus as a sea serpent remains null and void.
Konrad Gesner's version of
Olaus Magnus's anguilline sea serpent, as included in Gesner's Historiae
Animalium, 1558
Of course, there may indeed be eels of
gigantic length still eluding scientific detection in the vastness of the
oceans - giant anguillids, for example, that are compatible with
Heuvelmans's concept of the 'super eel' category of sea serpent - but unlike C. (or L.) giganteus, these have yet to be captured, preserved, and bottled.
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