Are Age Estimates for Longnose Gar and Spotted Gar Accurate? An Evaluation of Sagittal Otoliths, Pectoral Fin Rays, and Branchiostegal Rays

Opercle based age estimates of four redhorse species (Moxostoma anisurum, M. carinatum, M. macrolepidotum and M. valenciennesi) were compared with those from two structures that can be obtained non-lethally (scales and pectoral fin rays). For all species, age estimates from scales were significantly lower than those obtained from fin rays and opercles. After ages 4 to 5, age estimates from scales were consistently lower than those from the opercle. Overall differences between age estimates from fin rays and opercles were only detected for M. anisurum. For all species, age estimates from fin rays were consistently lower than opercles after ages 12 to 15. Closer agreement among different structures was identified for populations of M. macrolepidotum comprised of younger individuals. Maximum ages reported for Ontario populations were higher than those previously reported across the species’ ranges, reflecting either geographic differences in growth and longevity, or the historical use of scales for age estimation.

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Resurrection of the genus Homalopteroides (Teleostei: Balitoridae) with a redescription of H. modestus (Vinciguerra 1890)

Zootaxa ◽

10.11646/zootaxa.3586.1.31 ◽

2012 ◽

Vol 3586 (1) ◽

pp. 329 ◽

Cited By ~ 3

Author(s):

ZACHARY S. RANDALL ◽

LAWRENCE M. PAGE

Keyword(s):

Lateral Line ◽

Head Length ◽

Pectoral Fin ◽

Caudal Fin ◽

Dorsal Fin ◽

Interorbital Width ◽

Fin Rays ◽

Orbital Rim ◽

Pectoral Fin Rays ◽

Pelvic Fin

The genus Homalopteroides Fowler 1905 is resurrected and distinguished from the genus Homaloptera van Hasselt 1823based on a combination of characters including a unique mouth morphology, dorsal-fin origin over pelvic fin,≤60 lateral-line scales, and≤30 predorsal scales. Species included in Homalopteroides are H. wassinkii (Bleeker 1853), H. modestus(Vinciguerra 1890), H. rupicola (Prashad & Mukerji 1929), H. smithi (Hora 1932), H. stephensoni (Hora 1932), H. weberi(Hora 1932), H. tweediei (Herre 1940), H. indochinensis (Silas 1953), H. nebulosus (Alfred 1969), H. yuwonoi (Kottelat1998), and possibly H. manipurensis (Arunkumar 1999). Homalopteroides modestus (Vinciguerra 1890) is a poorlyknown species that was originally described from the Meekalan and Meetan rivers of southern Myanmar. It occurs in theSalween, Mae Khlong, and Tenasserim basins, and can be distinguished from all other species of Homalopteroides by thecombination of caudal-fin pattern (black proximal and distal bars, median blotch), 15 pectoral-fin rays, pectoral-fin lengthgreater than head length, 5½–6½ scales above and 5–6 scales below the lateral line (to the pelvic fin), 39–44 total lateral-line pores, no axillary pelvic-fin lobe, pelvic fin not reaching anus, orbital length less than interorbital width in adult, and maxillary barbel reaching to or slightly past the anterior orbital rim.

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