48 



Fig.21: Diagrammatic dorsal 

 view of the olfactory rosette 

 of some species of Phoxinus. 

 A: P. phoxinus (KU 22853. 

 56.4 mm SL): B: P. erythro- 

 gaster (KU 3895. 63.1 mm 

 SLr.O.P eos (KU 4578. 41.8 

 mm SL): D: P. neogaeus (UT 

 44.2894. 25.0 mm SL): E: P. 

 neogaeus (KU 14254. 51.8 

 mm SL). Scale bars = 1 mm. 



Primary lamellae (Fig.21A-E): Chen (1988b) reported different shapes of primary la- 

 mellae in cyprinids, such as oar-shaped (e.g.. Saurogobio dabryi), and hooked-shaped (e.g.. 

 Diptychus pachycheilus). Shape of the primary lamellae varies intra- and intergenerically 

 in cyprinids (Chen 1988b). In adult specimens of Phoxinus species, the primary lamellae 

 are oar-shaped and placed at the lateral and medial sides of the axis which is elongated 

 and located at the median of the olfactory organ from the anterior margin to the middle 

 of the organ. Variations of the primary lamellae are present in the shape of its dorsal mar- 

 gin and the number of the primary lamellae. 



The dorsal margin of the primary lamellae is convex in the species of Phoxinus. There- 

 fore the convex portion is higher than rest of the dorsal margin. In P. phoxinus and erxthro- 

 gaster, the highest portion of the dorsal margin of primary lamellae is close to the axis 

 (TS 5[1], Fig.21A-B). In all other species of Phoxinus. such as P. brachyurus. neogaeus. 

 and in the outgroups, the highest portion is positioned off the axis (TS 5[0], Fig.21C). 

 Number of primary lamellae in adult individuals of the same species does not change 

 significantly within species (Chen 1988b. Chen & Arratia 1994). though the number varies 

 ontogenetically. In cyprinids the number of primary lamellae varies from 10 (e.g.. Phoxinus 

 eos) to 60 (e.g.. Mylopharyngodon piceus) (Chen 1988b). In Phoxinus. the number of 

 primary lamellae varies from 10 (P. eos) to 16 (P. phoxinus). In P. phoxinus. 16 primary 

 lamellae are present (TS 6[1]): in all other Phoxinus species and in the outgroups. the 

 number of the lamellae is 10-13 (TS 6[0]) (Tab.l >. 



