Maternal Output in Polar Fish Reproduction
Jocgen S. Christiansen', Svein E. Fevolden 2 , Oleg V. Karamushk0 3 , and
Larisa I. Karamushk0 3
'Norwegian Institute of Fisheries and Aquaculture, 9005 Troms"" Norway
2The Norwegian College of Fishery Science, University of Troms"" 9037
Troms"" Norway
3Murmansk Marine Biological Institute, 183010 Murmansk, Russia
Introduction
In oviparous fish, the combination of egg size and fecundity (i.e. the total
number of eggs to be spawned) that propagates the largest number of
viable offspring is deemed to be favored by evolutionary processes [1,2].
Polar marine fish species tend to produce fewer and larger yolk-rich eggs
than their lower latitude counterparts. Rass [3] stated: "The size of eggs of
aquatic animals is in accordance with their breeding temperatures" and " ...
the eggs being greater, the nearer to the pole lies the habitat of the species."
The hypothesis that the physical environment (i.e. temperature)
conditions the increase in egg size towards higher latitudes was, however,
opposed by Marshall [4]. He argued that the observed latitudinal cline in
egg size and fecundity could be ascribed to sundry behavioral and
ecological factors, e.g. feeding conditions, rather than to a single physical
variable, such as breeding temperature, per se. The period of egg
incubation (i.e. the time between fertilization and hatching) does not seem
to correlate with egg size within fish species at anyone temperature [5] but
large eggs tend to result in large larvae [5,6]. Large larvae subsist longer on
endogenous fuel, are less affected by variations in exogenous food supply
and this may result in more viable offspring [7].
According to [4], the adaptive value of fish producing relatively large
eggs and thus more robust larvae is particularly relevant in habitats which
are characterized by relatively sparse food concentrations e.g. the deep-sea
and open oceanic waters. Polar fish are also subjected to seasonality
extremes in food availability: a short period of high production of
planktonic organisms is followed by long periods with little or no food in
the water column [8]. Thus, Marshall's hypothesis [4] would also apply to
polar fish species.
O. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer- Verlag !talia 1998
Jocgen S. Christiansen', Svein E. Fevolden 2 , Oleg V. Karamushk0 3 , and
Larisa I. Karamushk0 3
'Norwegian Institute of Fisheries and Aquaculture, 9005 Troms"" Norway
2The Norwegian College of Fishery Science, University of Troms"" 9037
Troms"" Norway
3Murmansk Marine Biological Institute, 183010 Murmansk, Russia
Introduction
In oviparous fish, the combination of egg size and fecundity (i.e. the total
number of eggs to be spawned) that propagates the largest number of
viable offspring is deemed to be favored by evolutionary processes [1,2].
Polar marine fish species tend to produce fewer and larger yolk-rich eggs
than their lower latitude counterparts. Rass [3] stated: "The size of eggs of
aquatic animals is in accordance with their breeding temperatures" and " ...
the eggs being greater, the nearer to the pole lies the habitat of the species."
The hypothesis that the physical environment (i.e. temperature)
conditions the increase in egg size towards higher latitudes was, however,
opposed by Marshall [4]. He argued that the observed latitudinal cline in
egg size and fecundity could be ascribed to sundry behavioral and
ecological factors, e.g. feeding conditions, rather than to a single physical
variable, such as breeding temperature, per se. The period of egg
incubation (i.e. the time between fertilization and hatching) does not seem
to correlate with egg size within fish species at anyone temperature [5] but
large eggs tend to result in large larvae [5,6]. Large larvae subsist longer on
endogenous fuel, are less affected by variations in exogenous food supply
and this may result in more viable offspring [7].
According to [4], the adaptive value of fish producing relatively large
eggs and thus more robust larvae is particularly relevant in habitats which
are characterized by relatively sparse food concentrations e.g. the deep-sea
and open oceanic waters. Polar fish are also subjected to seasonality
extremes in food availability: a short period of high production of
planktonic organisms is followed by long periods with little or no food in
the water column [8]. Thus, Marshall's hypothesis [4] would also apply to
polar fish species.
O. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer- Verlag !talia 1998