These species inhabit the nearshore environment of the bay where the sandy bottom is covered by macroalgae. The main differences in life history traits between S. taenionotus and S. abaster respectively can be summarized as follows: life span is c24 vs 17 mo; reproductive season begins in February vs March, and lasts 5 vs 4 mo; average length of fingerlings at the time they hatch from the male brood pouch is 20.3(±1.2) vs 13.5(±1.0) mm; egg incubation period is 2 mo vs 1 mo; average number of ripe eggs per mature ovary is 46(±9) vs 104(±40); average number of embryos incubated by male is 84(±17) vs 109(±27). The sex ratio in the reproductive population is more male-biased in S. taenionotus. The two species probably do not compete for food resources, remaining almost completely segregated in different foraging micro-habitats during most of their life span. The new-born spring individuals of both species feed almost exclusively on harpacticoids of the genus Tisbe. As they mature, S. abaster continue to prey on phytal organisms while the larger S. taenionotus become zooplanktivorous. -from Authors
Life cycles and feeding habits of Syngnathus taenionotus and S. abaster (Pisces, Syngnathidae) in a brackish bay of the Po River Delta (Adriatic Sea)
FRANZOI, Piero;ROSSI, Remigio;CECCHERELLI, Victor Ugo
1993
Abstract
These species inhabit the nearshore environment of the bay where the sandy bottom is covered by macroalgae. The main differences in life history traits between S. taenionotus and S. abaster respectively can be summarized as follows: life span is c24 vs 17 mo; reproductive season begins in February vs March, and lasts 5 vs 4 mo; average length of fingerlings at the time they hatch from the male brood pouch is 20.3(±1.2) vs 13.5(±1.0) mm; egg incubation period is 2 mo vs 1 mo; average number of ripe eggs per mature ovary is 46(±9) vs 104(±40); average number of embryos incubated by male is 84(±17) vs 109(±27). The sex ratio in the reproductive population is more male-biased in S. taenionotus. The two species probably do not compete for food resources, remaining almost completely segregated in different foraging micro-habitats during most of their life span. The new-born spring individuals of both species feed almost exclusively on harpacticoids of the genus Tisbe. As they mature, S. abaster continue to prey on phytal organisms while the larger S. taenionotus become zooplanktivorous. -from AuthorsI documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
