Age and growth of the lizardfish Saurida elongata from the Tsushima/Korea Strait

Abstract

We studied the age and growth of the lizardfish Saurida elongata using ground thin sections of otoliths (sagittae) from specimens collected in the Tsushima/Korea Strait between May 1999 and June 2001. A total of 695 individuals with fork lengths (FL) ranging from 189 to 478 mm were examined. The frequency of translucent zone occurrence at the outer margin of the otoliths indicated that translucent zones formed once a year between November and February. Most of the males examined were estimated to be 2-7 years old and the females, 3-9 years old. The maximum estimated age of a male specimen was 10 years and that of a female, 11 years. The estimated von Bertalanffy growth curves were FL t = 451{1 -exp[-0.172(t ? 2.50)]} and FL t = 515{1 -exp [-0.151(t ? 2.47)]} for males and females, respectively. At all ages, the FL at a specific age for females was greater than that for males, suggesting that females of this species grow faster than males.

Length-Weight Relationships and Otolith-Based Growth Curves for Brushtooth Lizardfish off Taiwan With Observations of Region and Aging–Material Effects on Global Growth Estimates

“…Brushtooth lizardfish have one prolonged spawning season (Wu et al, 2014;Mali et al, 2017). Migration has also been reported for a similar species S. elongate whose nursery ground was in a shallow bay but a few adults were caught in the region (Sakai et al, 2009). Thus, the potential for systematic errors could not be avoided for LFD and could affect its representativeness of the true size distribution (Heery and Berkson, 2009).…”

“…Both sagittal and transverse sections showed distinct annuli, but transverse otolith sections (IAPE = 1.08%) were generally more definite and provided more precise and consistent age estimates (deltaAIC = 2.45, p = 0.05) than those of sagittal sections (IAPE = 3.34%). Previous studies (e.g., Hining et al, 2000;Sakai et al, 2009) have recognized the potential of sagittal sectioning as a more efficient alternative to transverse sectioning because sagittal surfaces were much easier and less costly to prepare. However, Hining et al (2000) also commented that sagittal sections may underestimate rainbow trout ages due to natural calcium deposition on the sulcus.…”

“…One of the two sagittal otoliths was prepared in transverse section and the other in sagittal section (Supplementary Figure 1). The sagittal sections were prepared by embedding the whole sagitta otolith, adhered on a glass slide, and then polishing with sandpaper (1200 to 4000 grit) until the core became visible (Sakai et al, 2009). The transverse sections were prepared by embedding otoliths in epoxy resin, heating them to 60°C for 90 minutes, and then sectioning them transversely with an IsoMetTM low speed saw (approximately 500μm thick).…”

“…This is common for older, slowgrowing fish (Chilton and Beamish, 1982). In general, the time for preparing sagittal sections (grinding down the distal surface of the otolith to the midline) is about 10% of that required for preparing transverse sections (a cross section of the otolith taken though the dorsal to ventral surfaces) (Sakai et al, 2009).…”

Modeling of available size selectivity of the SURF-BRD for shrimp beam trawl

“…In contrast, the 50 % selection TL of the FP was 112 mm in the improved type (Table 6), and thus in order to retain all lizard fish of the target size, a smaller mesh size for the FP would be better. However, the minimum maturity sizes of male and female lizard fish have been reported to be 235 and 249 mm, respectively, for the slender lizard fish Saurida elongate [40] and 180 and 228 mm, respectively, for Saurida umeyoshii [41]. From the point-of-view of fisheries resources management for lizard fishes, the FP mesh size should be greatly enlarged.…”