50
J.S. Christiansen et al.
• For a given mode of oviposition, maternal output does not differ
between polar and boreal species.
• Maternal output is significantly higher in species (body length < 300
mm) with pelagic than in those with demersal oviposition. It should be
noted that there need not be an obvious relationship between maternal
output and the energetic costs of reproduction [21]. Maternal output, as
we define it, merely reflects the volume of eggs spawned without any
consideration of the energetic costs involved in e.g. the gonad
development (very long among Antarctic species), the energetic content
of ova (usually higher in demersal eggs) [22], spawning behavior and,
among some species, parental care (see [23] for a comprehensive
discussion). However, one might expect that a high maternal output
would also require a relatively large amount of energy to be invested.
In conclusion, maternal output is linked to mode of oviposition in
phylogenetically distant species and not directly with latitude (i.e.
boreal vs polar). However, maternal output of polar fish may be lower
than that of boreal species. This is not due to the low temperatures of
the habitat per se, but rather because many polar species are smallsized and have demersal oviposition. Consequently, our results
corroborate with the suggestion made by Marshall [4], that behavioral
and ecological factors seem to be the major determinants governing
reproductive traits of marine teleost fish.
Acknowledgments
We wish to thank Prof. A. Clarke, Dr. G. Hubold, Prof. M. Jobling, Dr. K.-H.
Kock, Dr. A.W. North and Dr. M.G. White for valuable comments.
References
1. Economou AN (1991) Is dispersal of fish eggs, embryos and larvae an
insurance against density dependence? Env BioI Fish 31: 313-321
2. Wootton RJ (1994) Life histories as sampling devices: optimum egg size
in pelagic fishes. J Fish BioI 45: 1067-1077
3. Rass TS (1941) Analogous or parallel variations in structure and
development of fishes in northern and Arctic Seas. Jubilee Publications of
the Moscow Society of Naturalists 1805-1940: 1-60 (in Russian, summary
in English)
4. Marshall NB (1953) Egg size in Arctic, Antarctic and deep-sea fishes.
Evolution 7: 328-341
J.S. Christiansen et al.
• For a given mode of oviposition, maternal output does not differ
between polar and boreal species.
• Maternal output is significantly higher in species (body length < 300
mm) with pelagic than in those with demersal oviposition. It should be
noted that there need not be an obvious relationship between maternal
output and the energetic costs of reproduction [21]. Maternal output, as
we define it, merely reflects the volume of eggs spawned without any
consideration of the energetic costs involved in e.g. the gonad
development (very long among Antarctic species), the energetic content
of ova (usually higher in demersal eggs) [22], spawning behavior and,
among some species, parental care (see [23] for a comprehensive
discussion). However, one might expect that a high maternal output
would also require a relatively large amount of energy to be invested.
In conclusion, maternal output is linked to mode of oviposition in
phylogenetically distant species and not directly with latitude (i.e.
boreal vs polar). However, maternal output of polar fish may be lower
than that of boreal species. This is not due to the low temperatures of
the habitat per se, but rather because many polar species are smallsized and have demersal oviposition. Consequently, our results
corroborate with the suggestion made by Marshall [4], that behavioral
and ecological factors seem to be the major determinants governing
reproductive traits of marine teleost fish.
Acknowledgments
We wish to thank Prof. A. Clarke, Dr. G. Hubold, Prof. M. Jobling, Dr. K.-H.
Kock, Dr. A.W. North and Dr. M.G. White for valuable comments.
References
1. Economou AN (1991) Is dispersal of fish eggs, embryos and larvae an
insurance against density dependence? Env BioI Fish 31: 313-321
2. Wootton RJ (1994) Life histories as sampling devices: optimum egg size
in pelagic fishes. J Fish BioI 45: 1067-1077
3. Rass TS (1941) Analogous or parallel variations in structure and
development of fishes in northern and Arctic Seas. Jubilee Publications of
the Moscow Society of Naturalists 1805-1940: 1-60 (in Russian, summary
in English)
4. Marshall NB (1953) Egg size in Arctic, Antarctic and deep-sea fishes.
Evolution 7: 328-341