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Estimating
Fish Size from Archaeological Bones within one Family: a Detailed Look at
three Species of Labridae. Foss
Leach & Janet Davidson |
| ABSTRACT:
The allometric relationships between bone dimension and live fish size (fork
length and ungutted weight) are examined in detail for three species of
the Labridae family which are common in temperate New Zealand waters.
These fish are not able to be identified more precisely than to family
level using the five paired cranial bones normally used for identification.
This suggests that we may be forced to use regression equations based on
the three species combined together to estimate live fish size. It was
found that some allometric relationships are very similar in all three
species, but others are not. Regression equations were calculated for each
species (N=122, 138, 126 respectively), and then for all species combined
(N=386). These equations are then used to estimate the fork length and
weight of a collection of Labridae fishes from an archaeological site at
Waihora in the Chatham Islands (N=3,095). Although the four catch size-frequency
diagrams are superficially similar, the estimated mean fork length and
mean fish weight are significantly different from one model to another.
Total meat weight varies by 10% depending on which model is employed.
Although in the meantime we may have to accept this level of imprecision,
we also suggest a method by which the combined fish catch can be separated
into its three components so that the approximate contribution of each
species to the total can be estimated.
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