Queen triggerfish Balistes vetula: Validation of otolith-based age, growth, and longevity estimates via application of bomb radiocarbon

Abstract

Ensuring the accuracy of age estimation in fisheries science through validation is an essential step in managing species for long-term sustainable harvest. The current study used Δ14 C in direct validation of age estimation for queen triggerfish Balistes vetula and conclusively documented that triggerfish sagittal otoliths provide more accurate and precise age estimates relative to dorsal spines. Caribbean fish samples (n = 2045) ranged in size from 67–473 mm fork length (FL); 23 fish from waters of the southeastern U.S. (SEUS) Atlantic coast ranged in size from 355–525 mm FL. Otolith-based age estimates from Caribbean fish range from 0–23 y, dorsal spine-based age estimates ranged from 1–14 y. Otolith-based age estimates for fish from the SEUS ranged from 8–40 y. Growth function estimates from otoliths in the current study (L∞ = 444, K = 0.13, t0 = -1.12) differed from spined-derived estimates in the literature. Our work indicates that previously reported maximum ages for Balistes species based on spine-derived age estimates may underestimate longevity of these species since queen triggerfish otolith-based ageing extended maximum known age for the species by nearly three-fold (14 y from spines versus 40 y from otoliths). Future research seeking to document age and growth population parameters of Balistes species should strongly consider incorporating otolith-based ageing in the research design.

Illuminating otoliths: New insights for life history of Balistes triggerfishes

“…( ) Combined L f = 520 [1e (À0.14(t+0.585)) ], ( ) male and ( ) female. L f , fork length (APE = 4.7%), combined with precision results on otoliths of B. vetula(APE = 3.6%)(Shervette & Rivera Hernández, 2022a), indicate that otoliths appear to provide more precise age estimates. Triggerfish sagittal otoliths are small, fragile and can be difficult to extract intact consistently without proper training, but despite these challenges, otoliths do provide accurate and precise age estimates(Rivera Hernández & Shervette, 2022).…”

“…In the Atlantic, grey triggerfish Balistes capriscus Gmelin, 1789, is an important component of commercial and recreational fisheries in the waters of South America (Bernardes, 2002 ), Central America (Castro‐Pérez et al ., 2018 ), western Africa (Ofori‐Danson, 1989 ; Shervette et al ., 2021 ), the Mediterranean (İşmen et al ., 2004 ; Kacem & Neifar, 2014 ) and North America (Allman et al ., 2018 ; Burton et al ., 2015 ). Another Balistes species, queen triggerfish B. vetula Linnaeus, 1758, also contributes to fisheries landings in the Atlantic waters of Brazil (Albuquerque et al ., 2011 ; Freitas Netto & Madeira di Beneditto, 2010 ), the Caribbean (Aiken, 1983 ; Matos‐Caraballo, 2018 ; Rivera Hernández et al ., 2019 ) and the south‐eastern United States (SEUS) waters (Shervette & Rivera Hernández, 2022a ; Stevens et al ., 2019 ).…”

“…From spine‐based age estimates, Balistes species were thought to exhibit moderately rapid growth (Aiken, 1983 ; Allman et al ., 2018 ; Kelly‐Stormer et al ., 2017 ), reach sexual maturity within the first 2 years of life (Aiken, 1983 ; Ingram, 2001 ; Moore, 2001 ) and were relatively short‐lived, attaining maximum ages of 14–15 years (Albuquerque et al ., 2011 ; Allman et al ., 2018 ; Burton et al ., 2015 ; Johnson & Saloman, 1984 ). However, recent age estimation validation studies utilizing regional patterns of bomb radiocarbon concluded that the first dorsal spine does not provide accurate age estimates for Balistes species (Patterson et al ., 2019 ; Shervette & Rivera Hernández, 2022a ). A study on B. vetula from the north Caribbean validated the accuracy of otolith‐based age estimation and demonstrated that spine‐based age estimates resulted in an erroneous characterization of population age structure, growth and longevity compared to the results from otolith‐based ages (Shervette & Rivera Hernández, 2022a ).…”

“…However, recent age estimation validation studies utilizing regional patterns of bomb radiocarbon concluded that the first dorsal spine does not provide accurate age estimates for Balistes species (Patterson et al ., 2019 ; Shervette & Rivera Hernández, 2022a ). A study on B. vetula from the north Caribbean validated the accuracy of otolith‐based age estimation and demonstrated that spine‐based age estimates resulted in an erroneous characterization of population age structure, growth and longevity compared to the results from otolith‐based ages (Shervette & Rivera Hernández, 2022a ). Our new understanding of the life‐history strategy of this species is that B. vetula is characterized by moderately slow growth and is long‐lived.…”

“…Patterson et al, 2019;Shervette & Rivera Hernández, 2022a), indicate that our past understanding of basic life-history parameters for the two Balistes species was flawed. B. capriscus and B. vetula were previously described as moderately rapidly growing and relatively short-lived(Burton et al, 2015;Manooch & Drennon, 1987) compared to other large-bodied reef fishes that support fisheries in the western Atlantic, but based on our new understanding from otolithbased ages we now know that Balistes species are moderately slow to slow growing and relatively long-lived.…”