THE BREEDINQ OF THE NORTH ATLANTIC FRESHWATER-EELS
147
VI. THE RETURN OF THE EUROPEAN EEL TO THE SEA
Tucker’s statement (1959a, p. 496) : “ Differences between morphological and physiological states of the European and American eels
on their descent to the sea are remarkable in a context quite apart from
taxonomy, The European eel is already well advanced towards being a
reproductive oceanic fish, and this despite the long journey which supposedly lies before it. The American eel, with a much smaller distance/
time to go, is yet relatively retarded. The two conditions are the
reverse of what any reasonable consideration of adaptive characters
and natural selection would predict.”
In support of this, Tucker firstly claims that the American eel is on
average a larger and four-times heavier fish.
Tucker cites only Vladykov (1955), who has studied the female eels
from the province of Quebec, Canada, one of the northernmost ranges,
where the American eel is fairly frequent (Schmidt, 1909, p. 125).
Vladykov has seen a female of 131b 5 0 2 , but also gives the average
weight of 1500 adult females as close to 3$ lh (1585 g), with an average
length of 36 in (91 cm). These are certainly large eels, but they do not
represent any typical population ; it is much more likely that this is the
case with specimens from the Gulf of Maine or Chesapeake Bay.
Hildebrand and Schroeder (1928, p. 115) have given the length and
weight in a series of which the two largest eels are 30 in (76 cm), 44.5 oz
(1276 g) and 30.1 in (76 cm), 33.9 oz (960 g).
But without entering into too many details I would just like to cite
Bigelow and Schroeder (1953, p. 151): “ Eels are said to grow to 4 f t
(122 cm) in length and to 164 lb (7460 g) in weight. Full-grown females
average only 2 to 34 ft (61 to 107 cm), however, and males are ~mallc;r.
Any eel more than 18 in (46 cm) long would probably be a female, and
one more than 24 in (61 cm) in length would certainly be one. The
smallest males are about 11 to 12 in (28 to 31 cm) long, females about
18 in (46 cm).” (The metric values added by me.)
This may be compared with the conditions of A . anguilh in Denmark ;
Otterstram (1914, p. 308) says (translated from Danish) : ‘‘ The eel is
said to reach a length of 150 cm and perhaps even a little more and a
weight of about 6 kg. Eels larger than 120 cm, 3 kg, are rare, a t least in
Denmark (Saltbaekvig, 1909, 123 cm, about 4 kg). The full-grown
females are a t least 42 cm ; usually they are 40 to 90 cm and weigh 1 to
14 kg; males are very rarely longer than 50 cm (the largest known was
51 cm) and weigh a t most 250 g ; the smallest full-grown males
observed were 29 cm.”
$ome figures from the Mediterranean may be mentioned. Heldt
I I
147
VI. THE RETURN OF THE EUROPEAN EEL TO THE SEA
Tucker’s statement (1959a, p. 496) : “ Differences between morphological and physiological states of the European and American eels
on their descent to the sea are remarkable in a context quite apart from
taxonomy, The European eel is already well advanced towards being a
reproductive oceanic fish, and this despite the long journey which supposedly lies before it. The American eel, with a much smaller distance/
time to go, is yet relatively retarded. The two conditions are the
reverse of what any reasonable consideration of adaptive characters
and natural selection would predict.”
In support of this, Tucker firstly claims that the American eel is on
average a larger and four-times heavier fish.
Tucker cites only Vladykov (1955), who has studied the female eels
from the province of Quebec, Canada, one of the northernmost ranges,
where the American eel is fairly frequent (Schmidt, 1909, p. 125).
Vladykov has seen a female of 131b 5 0 2 , but also gives the average
weight of 1500 adult females as close to 3$ lh (1585 g), with an average
length of 36 in (91 cm). These are certainly large eels, but they do not
represent any typical population ; it is much more likely that this is the
case with specimens from the Gulf of Maine or Chesapeake Bay.
Hildebrand and Schroeder (1928, p. 115) have given the length and
weight in a series of which the two largest eels are 30 in (76 cm), 44.5 oz
(1276 g) and 30.1 in (76 cm), 33.9 oz (960 g).
But without entering into too many details I would just like to cite
Bigelow and Schroeder (1953, p. 151): “ Eels are said to grow to 4 f t
(122 cm) in length and to 164 lb (7460 g) in weight. Full-grown females
average only 2 to 34 ft (61 to 107 cm), however, and males are ~mallc;r.
Any eel more than 18 in (46 cm) long would probably be a female, and
one more than 24 in (61 cm) in length would certainly be one. The
smallest males are about 11 to 12 in (28 to 31 cm) long, females about
18 in (46 cm).” (The metric values added by me.)
This may be compared with the conditions of A . anguilh in Denmark ;
Otterstram (1914, p. 308) says (translated from Danish) : ‘‘ The eel is
said to reach a length of 150 cm and perhaps even a little more and a
weight of about 6 kg. Eels larger than 120 cm, 3 kg, are rare, a t least in
Denmark (Saltbaekvig, 1909, 123 cm, about 4 kg). The full-grown
females are a t least 42 cm ; usually they are 40 to 90 cm and weigh 1 to
14 kg; males are very rarely longer than 50 cm (the largest known was
51 cm) and weigh a t most 250 g ; the smallest full-grown males
observed were 29 cm.”
$ome figures from the Mediterranean may be mentioned. Heldt
I I