On the daily formation of growth increments in the statolith of Japanese common squid, Todarodes pacificus (Preliminary study)

• Main Authors: Nakamura, Y., Sakurai, Y.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Hokkaido National Fisheries Research Institute 1990
• Subjects: DML
• Online Access: https://oceanrep.geomar.de/id/eprint/36506/; https://oceanrep.geomar.de/id/eprint/36506/1/2017.pdf

Japanese common squid, Todarodes pacificus, (DML=13-20cm) were maintained in a 12 tons tank for 29 days after capture. To mark the statolith, they were fed walleye pollock fry soaked tetracycline-HCl or strontium chrolide solution twice at an interval of 14 days. The mark with tetracycline was observed like a zone, not two bands, in the peripheral region of the ground statolith under UV light. Numbers of the growth increments from the beginning of the mark to the edge of statolith in 4 individuals were 18, 21, 21, and 23, respectively. The elapsed time from the first feeding of the fry added tetracycline to the sacrifice was 20 days. These results suggest that the growth increments are formed daily in the statolith of Japanese common squid. The mark with strontium in the ground statolith was not detected by the electron probe microanalyzer