Sensory Canal Pore Counts
As shown in Table 1, total canal pores in all bitterlings ranged from 23 to 40 (29-35 in Tanakia, 31-40 in Acheilognathus, and 23-39 in Rhodeus), with distribution as follows:.
SOC. Canal pores in all bitterlings except Rhodeus sinensis, which lacked this canal in the nasal bone, ranged from 6 to 10: 7-9 in Tanakia (Figs. 2A and 4), 6-10 in Acheilognathus (Figs. 2B, 5-6, and 7A), and 6-10 in Rhodeus (Figs. 3A, 7 B-D, and 8). Canal pores of R. sinensis, 5 to 6 (Fig. 3B).
IOC+TC. Canal pores in all bitterlings except R. sinensis, which lacked TC, ranged from 9 to 17: 9-13 in Tanakia, 10-15 in Acheilognathus, and 10-17 in Rhodeus. The reduced IOC in R. sericeus had a high number of canal pores (15-17 in R. sericeus amarus and 13-14 in R. s. sericeus) (Figs. 3A and 8D). Canal pores of R. sinensis, 9-11 (Fig. 3B).
PC+MC. Canal pores in all bitterlings ranged from 7 to 15: 9-12 in Tanakia, 10-15 in Acheilognathus, and 7-12 in Rhodeus. Canal pores of MC in R. o. kurumeus (Fig. 7C) were indistinct, and only PC pores were counted.
STC. Canal pores in all bitterlings except R. sinensis, which lacked STC (Fig. 3B), ranged from 1 to 3: 1-3 in Tanakia, 2-3 in Acheilognathus, and 1-2 in Rhodeus.
- Fig.2.
- Type I of the cephalic sensory canal system. A, Tanakia lanceolata. B, Acheilognathus longipinnis. Left, dorsal view; middle, lateral view; right, ventral view. IOC, infraorbital canal; MC, mandibular canal; PC, preopercular canal; SOC, supraorbital canal; STC, supratemporal canal; TC, temporal canal; TRC, trunk canal, an, anterior nostril; f, frontal; p, parietal; pn, posterior nostril; pt, pterotic. Scale bar=5 mm.
- Fig.3.
- Types II and III of the cephalic sensory canal system (Fig. A: Type II and Fig. B: Type III). A, Rhodeus sericeus sericeus. B, Rhodeus sinensis. Left, dorsal view; middle, lateral view; right, ventral view. Scale bar=5 mm.
- Fig.4.
- Cephalic sensory canal system in Tanakia (all figures: Type I). A, Tanakia limbata. B, T. tanago. C, T. himantegus chii. D, T. signifer. Left, dorsal view; middle, lateral view; right, ventral view. Scale bar=5 mm.
- Fig.5.
- Cephalic sensory canal system in Acheilognathus (all figures: Type I). A, Acheilognathus omeiensis. B, A. cyanostigma. C, A. yamatsutae. D, A. rhombeus. Left, dorsal view; middle, lateral view; right, ventral view. Scale bar=5 mm.
- Fig.6.
- Cephalic sensory canal system in Acheilognathus (all figures: Type I). A. Acheilognathus melanogaster. B, A. tabira tabira. C, A. tabira subsp. (a). D, A. macropterus. Left, dorsal view; middle, lateral view; right, ventral view. Scale bar=5 mm.
- Fig.7.
- Cephalic sensory canal system in Acheilognathus and Rhodeus (all figures: Type I). A, Acheilognathus typus. B, Rhodeus o. ocellatus. C, R. ocellatus kurumeus. D, Rhodeus atremius atremius. Left, dorsal view; middle, lateral view; right, ventral view. Scale bar=5 mm.
- Fig.8.
- Cephalic sensory canal system in Rhodeus (Figs. A to C: Type I, and Fig. D: Type II). A, Rhodeus fangi. B, R. atremius suigensis from Japan. C, R. atremius suigensis from China. D, Rhodeus sericeus amarus. Left, dorsal view; middle, lateral view; right, ventral view. Scale bar=5 mm.
- Table 1.
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Cephalic sensory canals, canal pores, trunk canal, and infraorbital bones in Tanakia, Acheilognathus, and Rhodeus.
Number of canal pores counted on left side of the body. Abbreviations of cephalic sensory canals follow text (see p. 5).
