Antarctic fish growth: profile of Trematomus newnesi

Abstract

Life history stages of the Antarctic Peninsula population of the notothenioid Trernaton~us newnesi were examined to gain insights into life history patterns and to understand population processes of ecologically important polar fishes. Sampling yielded 156 larvae and post-larvae and 236 juveniles and adults. Otoliths from these samples were examined for size, morphology and microstructure. External and internal examination of otoliths from 7. newnesi by scanning electron microscopy (SEM) revealed species-specific external shape, and internal rhythmlc patterns. No annual increments could b e identified in T newnesl otol~ths, but apparent daily increments and hatching marks were present. Tetracycline marlung of live f~s h indicated that increments were formed daily, despite extreme variation in photoperiod. Hatchlng season was estimated by back calculation of otolith increments to be from September to November, with recruitment to adulthood dt age 1 yr. Growth data conformed well to the Gompertz growth equation for juveniles and to the von B~rtalanffy equation for adults. F~s h grew slowly with the largest fish attaining 7 yr A multivariate mathematical model, relating age to otolith morphometrics and fish size, demonstrated that agc could be reliably determined from body and otolith measurements. This correlation makes it possible to age much larger samples of fish. The life-history profile of T newnesi may be typical of many polar fishes. Otolith methodology appears relevant for obtaining ages for large samples and for studying life history and population dynamics of polar fishes.

Review of the Early Life History of Antarctic Notothenioid Fish

“…There are seven published studies of the growth of antarctic fish larvae, based on sequential samples offish size, which cover a total of 14 species Keller 1983;Hubold 1985;Kellermann 1986a;Slosarczyk 1987;Radtke et al 1989;North 1990). These studies give growth rates up to 0.37mm SL day-!…”

“…There are, for example, some reports on the growth rates of larval notothenioids Keller 1983;Kellermann 1986a;Slosarczyk 1987;Radtke et al 1989;North 1990). This review focuses on development, morphology, pigmentation, community structure, diet and growth.…”

Age validation and growth of yolked larvae of <em>Patagonotothen tessellata</em> (Richardson, 1845) (Pisces: Nototheniidae) from the rocky littoral of the Beagle Channel, Argentina

“…To date, few studies have been done using microstructure analysis in Antarctic nototheniids (Hourigan and Radtke, 1989;Radtke et al, 1989;Radtke and Kellermann, 1991;Ruzicka and Radtke, 1995). The present study is the first for Subantarctic nototheniids.…”

“…The formation of daily rings in the otoliths of Antarctic larval fishes was first described by Townsend (1980) but microstructure technique was only employed in a few cases (Hourigan and Radtke, 1989;Radtke et al, 1989;Radtke and Kellermann, 1991;Ruzicka and Radtke, 1995).…”

Phenotypic plasticity in the Antarctic nototheniid fish Trematomus newnesi: a guide to the identification of typical, large mouth and intermediate morphs

“…It also may be found farther oVshore on the shelf to depths of 450 m (Tiedtke and Kock 1989). Its accessibility and local abundance have made it a frequent subject for both ecological studies (Radtke et al 1989;Vacchi and La Mesa 1995;La Mesa et al 2000;Barrera-Oro and Piacentino 2007) and physiological/biochemical/genetic work (D'Avino et al 1994;Hazel and Sidell 2004;Van Houdt et al 2006). It is unusual among notothenioids in exhibiting considerable phenotypic plasticity and exists as "typical" and "large mouth" morphs (Eastman and DeVries 1997) as well as a series of "intermediate" morphs (Piacentino and BarreraOro 2009).…”