The potential use of caudal thorns as a non-invasive ageing structure in the thorny skate (Amblyraja radiata Donovan, 1808)
Gallagher, M.J.; Green, M.J.; Nolan, C.P. (2006). The potential use of caudal thorns as a non-invasive ageing structure in the thorny skate (Amblyraja radiata Donovan, 1808). Environ. Biol. Fish. 77(3-4): 265-272. https://dx.doi.org/10.1007/s10641-006-9114-4
In: Environmental Biology of Fishes. Junk: The Hague. ISSN 0378-1909; e-ISSN 1573-5133, more
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Age
Bias
Musculoskeletal system > Anatomical structures > Skeleton > Endoskeleton > Bones > Vertebrae
Amblyraja radiata (Donovan, 1808) [WoRMS]
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| Authors | | Top |
- Gallagher, M.J.
- Green, M.J.
- Nolan, C.P.
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| Abstract |
The thorny skate, Amblyraja radiata, is the most widely distributed and abundant of all skate species worldwide, found on both sides of the north Atlantic Ocean. Large inter-regional size differences exist for this species and the few age and growth studies undertaken have revealed marked differences in life history traits for geographically distinct stocks. To facilitate the progression of further age and growth studies for this commercially important species, the effectiveness of caudal thorns as a rapid ageing tool was assessed. Twenty-eight male and 24 female thorny skates were collected off Greenland, covering the full size range of the species. Replicate age readings of crystal violet stained vertebral sagittal sections and whole silver nitrate stained caudal thorns revealed mean intra-reader age reading precision was higher for caudal thorns (Covariance (CV): reader 1 = 9.07, reader 2 = 9.73) than vertebrae (CV: reader 1 = 14.91, reader 2 = 14.27). Age bias plots revealed minimal inter-structure bias, apart from a higher average thorn age reading of 0.76 years from age classes 5–11 years for reader 1. Minor inter-reader bias was evident for vertebrae only; averaging 0.90 years higher for reader 1 from age classes 11 to 15 years. Preliminary evidence suggests caudal thorns could prove an effective non-invasive ageing tool for thorny skates. |
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