Notes: Otolith Morphology and Increment Validation in Young Lost River and Shortnose Suckers

Abstract

Morphology, time of formation and deposition of the first increment, and rate of increment deposition were determined for sagittae, lapilli, and asterisci from Lost River sucker Deliistes luxatus and shortnose sucker Chasmistes brevirostris. Sagittae and lapilli form on the day of hatch, and asterisci form after 41-52 d in Lost River sucker and after 14-25 d in shortnose sucker. Lapillus increments were validated by using known-age hatchery-raised larvae and wild-caught larvae and juveniles marked by immersion in water with an alizarin complexone concentration of 50 mg/L for 4 h and 18 h, respectively. A transition from relatively wide to relatively narrow increments was sometimes seen during the second week after hatch and appears to be associated with yolk absorption. Because of their readability and conservative growth, lapilli are the preferred otolith structure for age determination of larval and juvenile suckers, whereas sagittae are preferred for nonostariophysan fishes.

Otolith features and utility of lapillus for daily increment analysis in Opsaridium microcephalum (Cyprinidae) juveniles collected from Lake Malawi

“…2A) agreed with previous studies in cyprinids (Rosen and Greenwood, 1970;Hoff et al, 1997;Bestgen and Bundy, 1998;. The asteriscus is also considered inappropriate because of its ambiguous core (Fig.…”

“…2B). The asteriscus, in addition, is reported to be absent at hatching and to form later than the sagitta and lapillus in several species of cyprinids (Campana et al, 1987;Oxenford et al, 1994;Hoff et al, 1997). Fewer increment counts of the asterisci than those in the lapilli of the same specimens also support its inutility for reading increments.…”

“…For clarifying such aspects, otolith daily increment analysis has been broadly applied since Pannella (1971), and the sagitta has been utilized in most cases. However, the sagitta in the cyprinid, in general, is often inappropriate for daily increment observation because of its delicate structure (Rosen and Greenwood, 1970;Campana and Neilson, 1985), whereas the lapillus is suitable (Hoff et al, 1997;.…”

Effects of temperature, starvation and photoperiod on otolith increments in larval Chinese sucker, Myxocyprinus asiaticus

“…This means that increment width declined during the endogenous nutritional stage and the first several days of exogenous nutrition (the yolk sac was completely absorbed after 9-17 days in this study). This is remarkably consistent with the results from young Lost River and shortnose suckers, as in many lapilli and sagittae of these two suckers, a transition from relatively wide to relatively narrow increments occurred during the second week after birth, which was considered to be associated with yolk absorption and notochord flexion (Hoff et al 1997). However, in the later stage of starvation the increment width of starved larvae continued to decline, while those of fed larvae began to increase.…”

Comparison of daily increment formation pattern between sagittae and lapilli of ling (Genypterus blacodes) larvae and juveniles collected off Argentina

“…4). The existence of subdaily increments in sagittae has been reported in various earlier studies, e.g., Taubert & Coble (1977), Campana & Neilson (1982), Nishimura (1993), andHoff et al( 1997). Nishimura (1993) suggested that subdaily increments were often formed during the fast-growing phase in Theragra clacogramma, and Neilson & Geen (1982, 1984 reported that the multiple feeding per day caused multiple increments in otolith of Onchorhynchus tshawytscha.…”