Table 1.
Mean, minimum, and final times from fertilization to reach developmental stages at 18°C in the progeny of each Cobitis hybrid biotype and parental species
| Stages name | EE = 3 ♀ | TT = 2 ♀ | ET = 3 ♀ | ETT* | ETT clone 1 (6 ♀) | ETT clone 2 (4 ♀♂) | Characteristic | Fig. 2 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| mean | 1st | last | mean | 1st | last | mean | 1st | last | mean | mean | 1st | last | mean | 1st | last | |||
| 2 cells | 00:55 | 00:45 | 01:10 | 1:13 | 1:05 | 1:20 | 1:13 | 1:00 | 1:30 | 1:12 | 1:11 | 0:50 | 1:30 | 1:13 | 1:00 | 1:30 | 1st cleavage furrow | a |
| 4 cells | 01:31 | 01:20 | 01:45 | 1:43 | 1:35 | 1:50 | 1:42 | 1:35 | 1:50 | 1:33 | 1:29 | 1:10 | 1:45 | 1:38 | 1:25 | 1:55 | 2 × 2 array of blastomeres | b |
| 8 cells | 1:59 | 1:40 | 2:20 | 2:06 | 1:55 | 2:10 | 2:12 | 2:10 | 2:25 | 2:01 | 2:05 | 1:45 | 2:30 | 1:57 | 1:40 | 2:15 | 2 × 4 array of blastomeres | c |
| 32 cells | 3:22 | 2:55 | 3:40 | 3:16 | 3:00 | 3:25 | 3:19 | 3:00 | 3:40 | 3:22 | 3:25 | 3:00 | 3:40 | 3:20 | 3:00 | 3:35 | blastodisc with 32 cells assigned to the central part of the a. pole | d |
| Blastula | ||||||||||||||||||
| Dome – 30% epi | 11:20 | 10:25 | 12:00 | 11:15 | NA | NA | 11:57 | 11:00 | 13:00 | 12:31 | 12:13 | 11:30 | 13:10 | 12:49 | 12:15 | 13:30 | 30% of the yolk covered by the blastoderm | e |
| Gastrula | ||||||||||||||||||
| 50% epi | 12:28 | 11:15 | 13:20 | 14:10 | NA | NA | 14:00 | 13:00 | 15:00 | 14:09 | 14:11 | 13:30 | 14:50 | 14:07 | 13:45 | 14:30 | 50% of the yolk covered by the blastoderm | f |
| 100% epi | 20:58 | 20:00 | 21:45 | 20:55 | 19:00 | 20:00 | 24:18 | 24:00 | 25:00 | 24:16 | 23:25 | 21:45 | 25:30 | 25:07 | 24:45 | 25:30 | Tail bud prominent | g |
| 2 somites | 24:28 | 23:45 | 25:20 | 24:19 | 23:15 | 24:00 | 25:52 | 25:30 | 26:45 | 27:35 | 27:33 | 24:30 | 31:00 | 27:37 | 27:00 | 28:15 | First somatic furrow | h |
| 8 somites | 29:12 | 28:15 | 30:00 | 28:56 | 27:15 | 28:30 | 28:12 | 27:40 | 29:00 | 31:39 | 31:26 | 28:45 | 34:30 | 31:52 | 30:30 | 33:00 | Brain primordium, optic vesicle | i |
| 18 somites | 35:53 | 35:10 | 36:30 | 35:33 | 34:20 | 35:10 | 36:20 | 35:00 | 38:00 | 41:03 | 40:01 | 36:15 | 42:30 | 42:05 | 17:15 | 43:30 | Arrow indicates the optic vesicle | j |
| 34 somites | 50:25 | 48:40 | 52:00 | 48:30 | 48:30 | 49:50 | 50:10 | 48:00 | 52:00 | 56:15 | 55:20 | 51:30 | 58:00 | 57:11 | 56:15 | 58:00 | Median fin fold, tail extension, otolith [36]: | k |
| Hatching | ||||||||||||||||||
| Hatching | 75:30 | 68:00 | 82:00 | 76:30 | 70:00 | 80:00 | 78:10 | 72:00 | 85:00 | 81:23 | 80:06 | 72:00 | 90:00 | 82:41 | 74:00 | 90:00 | Pigmentation in retina and skin | l |
| 1st fry | 91:20 | 85:56 | 92:38 | 92:10 | NA | NA | 106:00 | 90:00 | 110:00 | 102:15 | 101:40 | 91:00 | 113:00 | 102:50 | 91:00 | 113:00 | Pigments appear in whole body, formation of pect. fins and exter. gills | m |
| 2nd fry | 108:00 | 101:40 | 108:13 | NA | NA | NA | 121:30 | 115:00 | 125:00 | 119:47 | 117:15 | 112:00 | 124:00 | 122:20 | 114:00 | 134:00 | Small pectoral fins, short exter. gills | n |
Time format: h:mm.
EE, C. elongatoides; TT, C. taenia; ET, diploid hybrid elongatoides x taenia; ETT, triploid hybrid; ETT*, pooled mean for both triploid clones; epi., epibole; a. pole, animal pole; epi., epiboly; pect., pectoral; exter., external; NA, not analyzed; 1st, time of first embryo which achieved particular developmental stage; last, time of last embryo which achieved particular developmental stage.