Segregate females into gravid and non-gravid so you have three groups. Are internal barnacles significantly more likely to affect one group than another? Which group, and how do you know?

Snail #	Sex (M,F,FG)	Size (mm)	Int. barnacles (#)	Ext. barnacles (#)
1	M	24.3	2	0
2	FG	17.7	0	1
3	F	21.2	1	0
4	F	25.5	0	1
5	M	19	0	1
6	F	2.6	1	1
7	FG	18.3	0	1
8	F	17.2	0	1
9	FG	28.9	1	1
10	FG	23.4	0	2
11	M	22.7	0	1
12	F	22	1	0
13	M	21.8	0	1
14	FG	20.9	0	1
15	FG	20.8	0	1
16	F	18.4	0	1
17	FG	24.2	0	2
18	M	21.3	0	1
19	FG	23.5	0	1
20	F	18.5	1	0
21	FG	24.6	2	0
22	F	23.3	1	0
23	F	23.1	2	0
24	M	26.3	1	1
25	FG	17.6	0	1
26	M	22	1	0
27	FG	22.7	0	2
28	F	23.5	0	1
29	F	23.2	1	0
30	FG	19.6	0	1
31	M	22.9	1	0
32	M	19.4	1	3
33	FG	18.5	0	1
34	FG	23.4	0	1
35	F	19.7	1	0
36	M	19.6	0	1
37	FG	19.8	0	1