Limnetic Stickleback

Data Sheet 1

Comparison of anatomical differences between inshore (benthic), offshore (limnetic) and F2 hybrid sticklebacks from Paxton Lake

(McPhail 1992)


Form: Benthic: Limnetic: F2 Hybrid:
Average body depth 10.6 mm 8.8 mm 9.7 mm
Percentage of population
with two dorsal spines
56% 2% 46%
Percentage of population
without pelvic girdle
81% 0.2% 37%
Average number of gill
rakers
18.7 23.8 20.6
Average gill raker length 0.8 mm 1.5 mm 1.2 mm
Average jaw width 3.7 mm 2.5 mm 3.2 mm
Average number of lateral
plates
0.7 11 6.9

Note:  F2 hybrids are the second generation offspring of a cross between benthic and limnetic sticklebacks. In other words, the offspring of a benthic/limnetic cross are interbred to give the F2 hybrids.


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