Abstract
This study examines the morphometric variation of lapilli otoliths in selected modern sea catfish species (Ariidae, Siluriformes) from northern Borneo. Given the pronounced similarity in otolith shape and anatomical features among these taxa, traditional taxonomic discrimination is often challenging, particularly at the species or genus level. To assess the taxonomic utility of otolith morphology, 216 otoliths from 12 species were analyzed using high-resolution imaging, a suite of shape indices (e.g., form factor, roundness), and precise measurements of defined ventral features (e.g., linea basalis). Seventeen morphometric parameters were subjected to various statistical analyses, including Principal Component Analysis (PCA), which delineated two major groups based on otolith shape. The rounded group comprised species from the genera Hexanematichthys, Netuma (two species), and Plicofollis (two species), while the elongated group included species from Arius (three species), Batrachocephalus, Cryptarius, Kyataphisa, and Osteogeneiosus. Subsequent statistical comparisons of selected morphological parameters revealed significant differences among some taxa. Hexanematichthys sagor exhibited a distinctly circular otolith morphology, characterized by a low aspect ratio (AR) and a uniquely oriented distal edge (AP6). Within the elongated group, although the parameters varied less, their combined assessment showed promise in differentiating certain taxa, such as Cryptarius and Osteogeneiosus, particularly through measurements of the otolith central area (R1), incisura linea basalis width (AP1), and otolith thickness ratio (R2). These findings demonstrate that even subtle morphological differences in otoliths can be quantitatively resolved to enhance taxonomic differentiation among ariid catfishes.
References
- Abdurahman, S.W., Ambak, M.A., Sheriff, S.M., Mohamed, S.Y.A.A. & Chowdhury, A.J.K. (2016) Morphological variations of Plicofollis species (Siluriformes: Ariidae) in Peninsular Malaysia: An insight into truss network approach. Sains Malaysiana, 45 (1), 1‒7.
- Acero, P.A. (2002) Order Siluriformes-Ariidae. In: The living marine resources of the western central Atlantic. FAO, Rome, pp. 831‒852.
- Acero, P.A. & Betancur-R, R. (2007) Monophyly, affinities, and subfamilial clades of sea catfishes (Siluriformes: Ariidae). Ichthyological exploration of freshwaters, 18 (2), 133.
- Aguilera, O.A., Moraes-Santos, H., Costa, S., Ohe, F., Jaramillo, C. & Nogueira, A. (2013) Ariid sea catfishes from the coeval Pirabas (Northeastern Brazil), Cantaure, Castillo (Northwestern Venezuela), and Castilletes (North Colombia) formations (early Miocene), with description of three new species. Swiss Journal of Palaeontology, 132 (1), 45‒68. https://doi.org/10.1007/s13358-013-0052-4
- Aguilera, O., Lopes, R.T., Rodriguez, F., dos Santos, T.M., Rodrigues-Almeida, C., Almeida, P., Machado, A.S. & Moretti, T. (2020) Fossil sea catfish (Siluriformes; Ariidae) otoliths and in-skull otoliths from the Neogene of the Western Central Atlantic. Journal of South American Earth Sciences, 2020, 102619. https://doi.org/10.1016/j.jsames.2020.102619
- Arroyo‐Zúñiga, K.I., Pacheco‐Ovando, R., Granados‐Amores, E., Granados‐Amores, J., González Ramírez, J. & Díaz‐Santana‐Iturrios, M. (2022) Lapillus otolith shape, a useful taxonomic feature for the identification of sea catfishes (Ariidae: Siluriformes) from the north‐eastern Pacific. Journal of Fish Biology, 101 (5), 1262‒1269. https://doi.org/10.1111/jfb.15198
- Betancur-R, R. (2009) Molecular phylogenetics and evolutionary history of ariid catfishes revisited: A comprehensive sampling. BMC Evolutionary Biology, 9 (1), 175. https://doi.org/10.1186/1471-2148-9-175
- Bond, C.E. (1996) Biology of Fishes. 2nd Edition. Saunders College Publisher, Fort Worth, Texas, 750 pp.
- Burgess, W.E. (1989) An atlas of freshwater and marine catfishes. A preliminary survey of the Siluriformes. TFH Publication, Neptune City, Canada, 28, 305‒325.
- Chen, Y. & Zhu, G. (2023) Using machine learning to alleviate the allometric effect in otolith shape-based species discrimination: the role of a triplet loss function. ICES Journal of Marine Science, 80 (5), 1277–1290. https://doi.org/10.1093/icesjms/fsad052
- Dantas, D.V., Barletta, M., Costa, M.F., Barbosa‐Cintra, S.C.T., Possatto, F.E., Ramos, J.A., Lima, A.R. & Saint‐Paul, U. (2010) Movement patterns of catfishes (Ariidae) in a tropical semi‐arid estuary. Journal of Fish Biology, 76 (10), 2540‒2557. https://doi.org/10.1111/j.1095-8649.2010.02646.x
- Farooq, N. & Panhwar, S.K. (2023) Taxonomic and Otolith Shape Parameters of Nine Sympatric Catfishes Commercially Harvested in Pakistan. Croatian Journal of Fisheries, 81 (1), 23‒32. https://doi.org/10.2478/cjf-2023-0003
- Ferraris, C.J. (2007) Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. Zootaxa, 1418 (1), 1‒628. https://doi.org/10.11646/zootaxa.1418.1.1
- Froese, R. & Pauly, D. (Eds.) (2024) FishBase. Version February 2024.World Wide Web electronic publication. Available from: https://www.fishbase.org (accessed 25 April 2025)
- Gauldie, R.W. & Crampton, J.S. (2002) An eco‐morphological explanation of individual variability in the shape of the fish otolith: comparison of the otolith of Hoplostethus atlanticus with other species by depth. Journal of Fish Biology, 60 (5), 1204‒1221. https://doi.org/10.1006/jfbi.2002.1938
- Hammer, Ø. (2023) PAST - PAleontological Statistics. Version 4.13, Reference manual. (PDF). Available from: https://www.fileeagle.com/software/download/16046/e249bd (accessed 10 May 2023)
- Kailola, P.J. & Bussing, W.A. (1995) Ariidae (frecuentemente ‘Tachysuridae’ en la literatura). In: Fischer, W., Krupp, F., Schneider, W., Sommer, C., Carpenter, K.E. & Niem, V.H. (Eds.), Guia FAO para la identificacion de especies para los fines de la pesca. Pacific centro-oriental. Vol. II. Vertebrados. Parte I. Food and Agriculture Organisation, Rome, pp. 860–886.
- Kailola, P.J. (1999) Order Siluriformes Ariidae. In: Carpenter, K.E. & Niem, V.H. (Eds.), The Living Marine Resources of the Western Central Pacific, 3, pp. 1827‒1847.
- Kocsis, L., Lin, C.H., Bernard, E. & Johari, A. (2024) Late Miocene teleost fish otoliths from Brunei Darussalam (Borneo) and their implications for palaeoecology and palaeoenvironmental conditions. Historical Biology, 36 (12), 2642–2676. https://doi.org/10.1080/08912963.2023.2271489
- Maciel, T.R., Vaz-dos-Santos, A.M., Barradas, J.R.D.S. & Vianna, M. (2019) Sexual dimorphism in the catfish Genidens genidens (Siluriformes: Ariidae) based on otolith morphometry and relative growth. Neotropical Ichthyology, 17, e180101. https://doi.org/10.1590/1982-0224-20180101
- Mahé, K., Gourtay, C., Defruit, G.B., Chantre, C., de Pontual, H., Amara, R., Claireaux, G., Audet, C., Zambonino-Infante, J.L. & Ernande, B. (2019) Do environmental conditions (temperature and food composition) affect otolith shape during fish early-juvenile phase? An experimental approach applied to European Seabass (Dicentrarchus labrax). Journal of Experimental Marine Biology and Ecology, 521, 151239. https://doi.org/10.1016/j.jembe.2019.151239
- Marceniuk, A.P. & Menezes, N.A. (2007) Systematics of the family Ariidae (Ostariophysi, Siluriformes), with a redefinition of the Genera. Zootaxa, 1416 (1), 1–126. https://doi.org/10.11646/zootaxa.1416.1.1
- Marceniuk, A.P., Menezes, N.A. & Britto, M.R. (2012) Phylogenetic analysis of the family Ariidae (Ostariophysi: Siluriformes), with a hypothesis on the monophyly and relationships of the genera. Zoological Journal of the Linnean Society, 165, 534‒669. https://doi.org/10.1111/j.1096-3642.2012.00822.x
- Marceniuk, A.P., Acero, A.P., Cooke, R.G. & Betancur-R, R. (2017) Taxonomic revision of the New World genus Ariopsis Gill (Siluriformes: Ariidae), with description of two new species. Zootaxa, 4290 (1), 1‒42. https://doi.org/10.11646/zootaxa.4290.1.1
- Marceniuk, A.P., Oliveira, C. & Ferraris Jr, C.J. (2024) A new classification of the family Ariidae (Osteichthyes: Ostariophysi: Siluriformes) based on combined analyses of morphological and molecular data. Zoological Journal of the Linnean Society, 200, 426–476. https://doi.org/10.1093/zoolinnean/zlad078
- Nolf, D. (1985) Otolithi piscium. In: Schultze, H. (Ed.), Handbook of paleoichthyology. Gustav Fischer Verlag, Stuttgart, pp. 1–146.
- Nolf, D. (2013) The diversity of fish otoliths, past and present. Royal Belgian Institute of Natural Sciences.
- Ohe, F. (2000) Otoliths of three species belonging to family Ariidae from East China Sea. Kaseki no Tomo, 47, 35‒42.
- Ohe, F. (2006) Skulls and otoliths of eleven sea catfishes (Family Ariidae) from Malaysia and one species related to them from the East China Sea. Natural Environmental Science Research, 19, 11‒28.
- Ponton, D. (2006) Is geometric morphometrics efficient for comparing otolith shape of different fish species? Journal of Morphology, 267 (6), 750‒757. https://doi.org/10.1002/jmor.10439
- Popper, A.N., Ramcharitar, J. & Campana, S.E. (2005) Why otoliths? Insights from inner ear physiology and fisheries biology. Marine and freshwater Research, 56 (5), 497‒504. https://doi.org/10.1071/MF04267
- Pusey, B.J., Jardine, T.D., Bunn, S.E. & Douglas, M.M. (2020) Sea catfishes (Ariidae) feeding on freshwater floodplains of northern Australia. Marine and Freshwater Research, 71 (12), 1628‒1639. https://doi.org/10.1071/MF20012
- Santificetur, C., Giaretta, M.B., Conversani, V.R.M., Brenha-Nunes, M.R., Siliprandi, C.C. & Rossi-Wongtschowski, C.L.D.B. (2017) Atlas of marine bony fish otoliths of Southeastern-Southern Brazil Part VIII: Siluriformes (Ariidae) and Pleuronectiformes (Achiridae, Paralichthyidae, Cynoglossidae). Brazilian Journal of Oceanography, 65 (3), 448‒494. https://doi.org/10.1590/s1679-87592017143106503
- Santos, L. & Vaz-dos-Santos, A.M. (2023) Insights of otoliths morphology to reveal patterns of teleostean fishes in the Southern Atlantic. Fishes, 8 (1), 21. https://doi.org/10.3390/fishes8010021
- Simier, M., Osse, O.J.F., Sadio, O. & Ecoutin, J.M. (2021) Biology and ecology of sea catfish (Ariidae) of estuarine, lagoon and coastal ecosystems in West Africa. Journal of Fish Biology, 99 (2), 629‒643. https://doi.org/10.1111/jfb.14751
- Souza, A.T., Soukalová, K., Děd, V., Šmejkal, M., Blabolil, P., Říha, M., Jůza, T., Vašek, M., Čech, M., Peterka, J., Vejřík, L., Vejříková, I., Tušer, M., Muška, M., Holubová, M., Boukal, D.S. & Kubečka, J. (2020) Ontogenetic and interpopulation differences in otolith shape of the European perch (Perca fluviatilis). Fisheries Research, 230, 105673. https://doi.org/10.1016/j.fishres.2020.105673
- Tuset, V.M., Farré, M., Otero-Ferrer, J.L., Vilar, A., Morales-Nin, B. & Lombarte, A. (2016) Testing otolith morphology for measuring marine fish biodiversity. Marine and Freshwater Research, 67 (7), 1037‒1048. https://doi.org/10.1071/MF15052
- Vignon, M. (2012) Ontogenetic trajectories of otolith shape during shift in habitat use: Interaction between otolith growth and environment. Journal of Experimental Marine Biology and Ecology, 420, 26‒32. https://doi.org/10.1016/j.jembe.2012.03.021
- Weisler, M.I. (1993) The importance of fish otoliths in Pacific Island archaeofaunal analysis. New Zealand Journal of Archaeology, 15, 131‒159.