Effects of Formalin on Length and Weight of Fishes

Journal of the Fisheries Research Board of Canada 04/2011; 20(6):1441-1455. DOI: 10.1139/f63-098

ABSTRACT Sockeye smolts, pink and chum fry, and pink and chum fingerlings (Oncorhynchus) were sequentially weighed and measured when alive and after death in water and after killing and storage in formalin up to 225 days. The fish shrank within 12 hours to 97% and by 30–40 days to 96% of live length. Further changes in length were not significant. These same relative changes were observed from fish of different sizes, and the values were not significantly different among groups preserved in formaldehyde solutions of fresh or sea water. In fresh water, fish gained weight while yet alive but under anaesthesia. In freshwater formalin, fish gained weight rapidly for 1 or 2 days, then lost weight at a decelerating rate to the time of last measurement. Fish killed and stored in salt water formalin lost weight for the first few days, then gained weight at a decelerating rate. Relative magnitudes and rates of change were inversely related to size of specimens contained in the sample. These changes had pronounced effects on relative condition factors which varied from 97 to 135% of live values depending upon size of fish, type of formalin and time in preservative.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present the results of analysis of the group growth of the Low Amur grayling Thymallus tugarinae from 18 rivers of the Low Amur basin, tributaries of the Bureya and Ussuri rivers. We made use of the published data on the fishes of Sakhalin Island. The dwarf and fast-growing forms are not revealed among the investigated groups of this species. The parameters of growth of the Low Amur grayling in the investigated rivers are different, which is determined by the different conditions of feeding migration connected with the geographical location of the streams, their hydrological features, density of populations, etc. The anthropogenic factor influence is essential. Growth rate of T. tugarinae is lower compared with the other Amur species of graylings.
    Journal of Ichthyology 08/2013; 52(9).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Measurements made on preserved anuran specimens are often used in studies of systematics, ecology and evolution. Here, we examine the effect of preservation on one of the most common measurement of frogs, snout-urostyle length (SUL). Preservation had significanteffects on the SUL of 13 of the 14 species of North American frogs included in this study, with all species decreasing in SUL by 0.31-5.62%. Smaller frog species did not shrink proportionally more or less than larger species. Absolute shrinkage was correlated with SUL and was greater in larger species. Within species, percent shrinkage was not significantly correlated with SUL in 10 species, but significantly greater for larger individuals in 3 species, and decreased with size in 1 species. Absolute shrinkage was statistically greater for larger individuals in 4 species. Our results agree with studies of morphological permutations in fish which show that most preservation-related changes take place within the first few months after initial preservation. We suggest that the potential consequences of using preserved specimens in research must be considered and that future studies continue to examine preservation effects, not only on frogs, but on all preserved specimens used in scientific investigations.
    Phyllomedusa : Journal of Herpetology. 01/2009;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Documenting long-term trends in mercury deposition and/or accumulation is important in setting regulatory benchmarks, modeling contaminant transfer and flux, measuring success of environmental controls, and even assigning responsibility for pollution. We conducted a study to compare mercury concentrations in small fishes from "high-mercury" and "low-mercury" regions of Illinois, as well as to examine historic patterns of mercury availability using preserved fishes. Mercury concentrations were greater in four species of small fishes collected from a stream in a "high-mercury" region than in those same taxa collected from a stream in a "low-mercury" area in Illinois. Mercury concentrations in blackstripe topminnows (Fundulus notatus) declined dramatically between 1900 and 1961/2006 in the "high-mercury" stream, presumably due reductions in mercury releases from local and regional sources. Preserved fish had an apparent increase in mercury concentrations for up to 12 months, which is consistent with changes in mass and loss of proteins observed in other studies, and we recommend that recent samples be preserved for at least 12 months before comparison with older fluid-preserved material. Based on our results, further studies of mercury in small fishes in Illinois streams appear warranted.
    Environmental Monitoring and Assessment 01/2013; · 1.68 Impact Factor


Available from