Wittmann 1992a
Wittmann 1992a
WITTMANN, K. J., 1992: Cyclomorphosis in temperate zone Mysidacea: evidence and possible adaptive and taxonomical significance. In: KÖHN J. & M.B. JONES & A. MOFFAT (Eds.), Taxonomy, Biology and Ecology of (Baltic) Mysids (Mysidacea, Crustacea). Rostock Univ. Press: 25-32.
Compared with summer Siriella jaltensis, winter and spring animals have longer thoracic appendages, even when body size differences are taken into account. Earlier observations of two species of Leptomysis also showed winter animals to have more spines or to be more setose than the summer generations. In these species, there are greater morphological and reproductive seasonal differences in individuals from the North Adriatic compared with those from the Gulf of Naples or Corse. This may be attributed to wider temperature and salinity changes in the North Adriatic.
To some extent, such cyclomorphic changes may be interpreted as adaptations compensating for effects of different body and/or brood weights during swimming. However, a strong relationship between cyclomorphosis and reproductive biology is evident. Seasonal changes of adult morphology may result from (a) a simple relationship between structure and body size, in combination with different sizes at attainment of sexual maturity; (b) different seasonal growth curves resulting in true cyclomorphosis; and (c) change of growth curves near attainment of sexual maturity resulting in a combination of (a) and (b). Such growth relationships pose severe problems for the morphological species concepts used in taxonomy..
Mediterranean; cyclomorphosis; growth; biometry; development; morphology
Mysidae; Leptomysis heterophila; Leptomysis lingvura adriatica; Siriella adriatica; Siriella jaltensis