EFFECTS OF FORMALDEHYDE AND ETHANOL PRESERVATION ON BODY AND OTOLITHSOF MAUROLICUS-MUELLERI AND BENTHOSEMA-GLACIALE

First of its kind, this study examines effects of preservatives on oto liths as well as on fish size and weight. Effects of 200 days of prese rvation in 4 % seawater formaldehyde solution and 80 % ethanol were in vestigated for the two small, mesopelagic fishes, Benthosema glaciale (REINHARDT, 1837), and Maurolicus muelleri (GMELIN, 1789). The body we ight loss was much higher in ethanol (37-39 %) than in formaldehyde (1 3-16 %). The decrease in standard length was small in both preservativ es and for both species (0.8-3 %). The weight of the otoliths of B. gl aciale was estimated to decrease by approximately 3 % in both formalde hyde and ethanol, while a radius change in one direction could not be demonstrated unambiguously. In contrast, there were no significant cha nges in the otoliths of M. muelleri in any of the preservatives, thus we can use otoliths from M. muelleri preserved for up to at least 200 days in correctly buffered formaldehyde. Growth rate and age can then easily be coupled with other life history parameters obtained from pre served fish.