For comparative purposes, e.g. to find patterns in parameter values among species, it helps to judge the completeness of the data
using a marking system from 0 (low) to 10 (high)
(The publication: Lika et al 2011
The following system is used, where the criterion for each level includes the criteria for all lower levels
- maximum length and body weight; length as function of weight
- age, length and weight at birth and puberty for one food level
- reproduction and feeding as function of age, length and/or weight at one food level
- growth (curve) at several (> 1) food levels; age, length and weight at birth and puberty at several food levels
- reproduction and feeding as function of age, length and/or weight at several (> 1) food levels
- respiration as function of length or weight and life span at several (> 1) food levels
- elemental composition at one food level, survival due to ageing as function of age
- elemental composition at several (> 1) food levels, including composition of food
- elemental balances for C, H, O and N at several body sizes and several food levels
- energy balance at several body sizes and several food levels (including heat)
It can happen that some data of lower levels are not available or that some information from higher levels is available; the mark should then be reduced or increased somewhat.
This marking method cannot be 'exact' and should be treated as an indicator only.
Since it is impossible to obtain energy balances without having mass balances, or to obtain mass balances without having composition data,
the highest levels do not occur in the latter list.