| Main Ref. | Domínguez-Domínguez, O., D.M. Bernal-Zuñiga and K.R. Piller, 2016 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | always different morphology between mature adults |
| Different colors | always different colors between mature adults |
| Remarks | Coloration varies with respect to age and sex. |
| Striking features | |
| Body shape lateral | |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | |
| Diagnosis |
Xenotoca lyonsi differs from the congeners occurring in the Pacific Coast drainages by the combination of the following characters (none unique to the species): females posses 13 dorsal rays (vs. 15 or 16 in X. melanosoma and 14 in X. doadrioi); for males and females the differences are as follows: 14 anal fin rays (vs. 15 or 16 in X. melanosoma), 12 pectoral fin rays (vs. 13 in Xenotoca eiseni), 8 caudal peduncle scales (vs. 9 in Xenotoca eiseni and X. melanosoma), 30-31 scales in a lateral series (vs. 32 in X. doadrioi), 9 transversal scales (vs. 11 or 12 in X. eiseni and X. doadrioi) and 11 suparorbital pores (vs. 10 in X. doadrioi). Both male and female have a smaller eye diameter (head lengthL/ eye diameter = 3.7 vs. 3.0 in X. doadrioi and 3.5 in X. eiseni for females, and head length/ eye diameter= 3.6 vs. 3.3 in X. eiseni in males), high dorsal fin base (standard length /dorsal fin base length = 6.5 vs. 6.9 in X. eiseni for females and and 5.5 vs. 5.9 in X. eiseni in males) (Ref. 117630). |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | |
| Scales in lateral series | 30 - 31 |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | 7 - 9 |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | no striking attributes |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | 12 - 14 |
| Adipose fin | absent |
| Attributes | more or less truncate |
| Fins number | |
| Spines total | |
| Soft-rays total | 13 - 14 |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays 11 - 13 | |
| Pelvics | Attributes more or less normal |
| Position abdominal before origin of D1 | |
| Spines | |
| Soft-rays |