**Appendix A**

**Figure A1.** Mean (points) and range (95% confidence interval) of differences in growth zone counts derived from MO2 (**a**) and MO3 (**b**) between two independent readers at the counts for the first reader (**left**) and difference between methods at the counts for MO1 (**c**) and at the counts for MO3 (**d**) for *L. intermedius* and *L. tsanensis* in Lake Tana (**right**). The horizontal solid line is the 1:1 equivalence line and marginal histograms are for growth zone counts of the first reader (**top**) and differences in growth zone counts between readers and methods.

**Figure A2.** Mean (points) and range (95% confidence interval) of differences in growth zone counts derived from MO2 (**a**) and MO3 (**b**) between two independent readers at the counts for the first reader (**left**) and difference between methods at the counts for MO1 (**c**) and at the counts for MO3 (**d**) for *L. platydorsus* and *L. megastoma* in Lake Tana (**right**). The horizontal solid line is the 1:1 equivalence line and marginal histograms are for growth zone counts of the first reader (**top**) and differences in growth zone counts between readers and methods.

#### **Appendix C**

**Table A1.** Statistical tests (regression and paired t-test) for the detection of bias of growth zone counts of the endemic *Labeobarbus* species between readers and methods.


#### **References**

1. Nagelkerke, L.A.; Sibbing, F.A.; van den Boogaart, J.G.; Lammens, E.H.; Osse, J.W. The barbs (Barbus spp.) of Lake Tana: A forgotten species flock? *Environ. Biol. Fishes* **1994**, *39*, 1–22. [CrossRef]

2. Anteneh, W.; Getahun, A.; Dejen, E.; Sibbing, F.A.; Nagelkerke, L.A.J.; De Graaf, M.; Wudneh, T.; Vijverberg, J.; Palstra, A.P. Spawning migrations of the endemic Labeobarbus (Cyprinidae, Teleostei) species of Lake Tana, Ethiopia: Status and threats. *J. Fish Biol.* **2012**, *81*, 750–765. [CrossRef] [PubMed]


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