Swordfish, Xiphias gladius Linnaeus 1758


Other Names: Broadbill, Broadbill Swordfish

An illustration of a Swordfish, Xiphias gladius, from Cuvier & Valenciennes, 1828, Histoire naturelle des poissons.. Source: Biodiversity Heritage Library. License: Public Domain

Summary:

A large, powerful oceanic predator with a long cyclindrical, tapering body, and an extremely long, flattened, sword-like bill, used to slash prey. Swordfish are blackish-brown above, fading to a lighter brown on the underside. As adults, they lack pelvic fins, scales and teeth, and have a high dorsal fin and a relatively large anal fin.

Like some shark and tuna species, Swordfish are endothermic, with the ability to maintain body temperatures above that of the surrounding water. A highly specialized heating system located in an extraocular muscle specifically warms the eyes and brain up to 10°C–15°C above ambient water temperatures. 

This important adaptation allows these highly visual oceanic predators to hunt their agile, cold-blooded prey in deep, cold waters (Fritsches et al. 2005).

Swordfish are highly valued as a commercial species and recreational species.


Cite this page as:
Dianne J. Bray & Sascha Schultz, Xiphias gladius in Fishes of Australia, accessed 15 Nov 2018, http://fishesofaustralia.net.au/home/species/2565

Swordfish, Xiphias gladius Linnaeus 1758

More Info


Distribution

A cosmopolitan species, distributed throughout tropical and sub-tropical waters, migrating to temperate waters during summer. Swordfish are widespread in Australian waters, usually beyond the continental shelf, in depths of 0-800 m. The species generally occurs above the thermocline, preferring water temperatures of 18-22 deg C.

Features

Dorsal fin (1) 0, 34-49; Dorsal fin (2) 4-6; Anal fin (1) 0, 13-14; Anal fin (2) 3-4; Pectoral fin 16-18. Pelvic fins absent.

Pectoral fins falcate, positioned low on body. Bill is long and flat in cross section. The lateral line is absent in adults, but visible in smaller specimens up to 1 m long. Teeth and scales absent in adults. Body is roughly cylindrical and elongate. First and second dorsal fins are well separated, but continuous in juveniles, first dorsal shrinking to adult proportions as the fish grows. Juveniles initially develop elongated upper and lower jaws, but lower jaw gradually reduces to adult shape. Juveniles also posses scales and have teeth in both upper and lower jaws.

Size

To a length of 450 cm (although usually smaller) and a weight of 600 kg. Females are generally larger than males, with most fish over 140 kg in weight being female.

Colour

Blackish-brown fading to light-brown below; first dorsal fin with blackish-brown membrane, other fins brown or blackish-brown.

Feeding

Slashes prey with its bill to stun or kill it before swallowing whole. Typical food items include pelagic fishes such as tuna, flying fish and barracudas, demersal prey includes hakes, gempylids and myctophids. Squid and cuttlefish species also form part of its prey. Large adults are known to hunt demersal species in temperatures as low as 5-10 degrees.

Biology

Australian east coast females mature at around 150 cm fork-length; males are mature at smaller sizes (around 1 m fork-length). Spawning occurs from September to March, but predominantly during the December to February period, apparently triggered by water temperatures above 24 degrees. Swordfish spawn near the surface and females produce pelagic eggs and the larvae are pelagic. Fecundity is related linearly to size. Each female spawns on multiple occasions (batch spawning), however the frequency of spawning and the number of times an individual female spawns has not been determined. During the spawning period to the sex ratio is skewed towards females, particularly in nearshore spawning areas. Worldwide the spawning season varies and may include the full year near the equator.

Fisheries

In Australian waters the species is fished both by Australian long-liners and Japanese ships. Catches in the eastern Australian portion of the fishery were around 2500 tonnes in 2001, and have fallen to 1600 tonnes in 2003.

The species is also fished as part of the Western Australian Tuna and Billfish fishery. Catches peaked at 2100 tonnes in 2001 but have since fallen to 1100 tonnes (2003).

Swordfish are targeted via the use of deep longlines or taken as bycatch on tuna longlines fished at night. Concerns have been raised that a large portion of the fish captured are immature, and that the fishery may be unsustainable.

Considered a good food fish, marketed as fillets. Recreational catches appear to be restricted to incidental catches while trolling surface lures for other billfish. The Australian linefishing record is 9.5 kg.

Conservation

IUCN Red List: Least Concern

Swordfish are highly migratory, and the species is listed in Annex I of the 1982 Convention on the Law of the Sea (FAO Fisheries Department 1994).

Remarks


Similar Species

Unlike the closely related marlins (Istiophoridae), adult Swordfish lack pelvic fins.

Etymology

From the Greek Xiphias meaning sword, and the Latin gladius meaning a flat sword, in reference to the flattened sword-like bill.

Species Citation

Xiphias gladius Linnaeus 1758, Systema Naturae Ed. X. 1: 248. Type locality: European ocean.

Author

Dianne J. Bray & Sascha Schultz

Resources

Australian Faunal Directory

Swordfish, Xiphias gladius Linnaeus 1758

References


Alvarado Bremer, J. R., Hinton, M.G. et al. 2006. Evidence of spatial genetic heterogeneit y in Pacific swordfish (Xiphias gladius) revealed by the analysis of ldh-A sequences. Bulletin of Marine Science 79(3): 493-503.

Alvarado Bremer, J.R., Mejuto, J., Greig, T.W. & Ely, B. 1996. Global population structure of the swordfish (Xiphias gladius) as revealed by analysis of the mitochondrial DNA control region. J. Exp. Mar. Biol. Ecol. 197: 295-310.

Block, B.A. 1986. Structure of the brain and eye heater tissue in marlins, sailfish and spearfish. J. Morphol. 190: 169–189.

Carey, F.G. 1982. A brain heater in the swordfish. Science 216: 1327–1329.

Carey, F.G. & B.H. Robison. 1981. Daily patterns in the activities of swordfish, Xiphias gladius, observed by acoustic telemetry. Fish. Bull. 79: 277–292.

Collette, B.B. 2010. Reproduction and Development in Epipelagic Fishes. In: Cole, K.S. (ed.), Reproduction and Sexuality in Marine Fishes: Patterns and Processes, University of California Press, Berkeley, CA.

Collette, B., Acero, A., Amorim, A.F., Bizsel, K., Boustany, A., Canales Ramirez, C., Cardenas, G., Carpenter, K.E., de Oliveira Leite Jr., N., Di Natale, A., Die, D., Fox, W., Fredou, F.L., Graves, J., Guzman-Mora, A., Viera Hazin, F.H., Hinton, M., Juan Jorda, M., Minte Vera, C., Miyabe, N., Montano Cruz, R., Masuti, E., Nelson, R., Oxenford, H., Restrepo, V., Salas, E., Schaefer, K., Schratwieser, J., Serra, R., Sun, C., Teixeira Lessa, R.P., Pires Ferreira Travassos, P.E., Uozumi, Y. & Yanez, E. 2011. Xiphias gladius. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. . Downloaded on 18 October 2012.

Collette, B.B., K.E. Carpenter, B.A. Polidoro, M.J. Juan-Jorda, A. Boustany, D.J. Die, C. Elfes, W. Fox, J. Graves, L.R. Harrison, R. McManus, C.V. Minte-Vera, R. Nelson, V. Restrepo, J. Schratwieser, C.-L. Sun, A. Amorim, M. Brick Peres, C. Canales, G. Cardenas, S.-K. Chang, W.-C. Chiang, N. de Oliveira Leite, H. Harwell, R. Lessa, F.L. Fredou, H.A. Oxenford, R. Serra, K.-T. Shao, R. Sumaila, S.-P. Wang, R. Watson, E. Yanez. High Value and Long Life - Double Jeopardy for Tunas and Billfishes. Science 333(6040): 291 DOI: 10.1126/science.1208730

Collette, B.B., McDowell, J.R. & Graves, J.E. 2006. Phylogeny of Recent billfishes (Xiphioidei). Bull. Mar. Sci. 79(3): 455-468.

De Metrio, G., Ditrich, H. & Palmieri, G. 1997. Heat-producing organ of the swordfish (Xiphias gladius): a modified eye muscle. Journal of Morphology 234:89-96. doi:10.1002/(SICI)1097-4687(199710)234:1<89::AID-JMOR8>3.0.CO;2-I

Fritsches, K.A., Brill, R.W. & Warrant, E.J. 2005. Warm Eyes Provide Superior Vision in Swordfishes. Current Biology 15: 55−58

Glover, C.J.M. 1994. Family Xiphiidae. 829, fig. 733 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs.

Habegger, M. L., Dean, M. N., Dunlop, J. W. C., Mullins, G., Stokes, M., Huber, D. R., Winters, D. & Motta, P. J. (2015). Feeding in billfishes: inferring the role of the rostrum from a biomechanical standpoint. Journal of Experimental Biology 218: 824-836. doi:10.1242/jeb.106146

Hernández-Garcia, V. 1995. The diet of the swordfish Xiphias gladius Linnaeus, 1758, in the central east Atlantic, with emphasis on the role of cephalopods. Fish. Bull. 93: 403–411.

Hopkin, M. 2005. Swordfish heat their eyes for better vision. Nature, 10 January 2005.

Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3)

Kailola, P.J., Williams, M.J., Stewart, P.C., Reichelt, R.E., McNee, A. & Grieve, C. 1993. Australian Fisheries Resources. Canberra : Bureau of Resource Sciences and the Fisheries Research and Development Corporation 422 pp.

Kolody, D., Campbell, R., Davies, N. 2008. A Multifan-CL stock assessment of the south-west Pacific swordfish 1952-2007. WCPFC-SC4-2008/SA-WP-6.

Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs.

Lynch A.W. (2004). Southern and Western Tuna and Billfish Fishery Data Summary 2003. Logbook Program, Australian Fisheries Management Authority, Canberra.

Lynch A.W. (2005). Eastern Tuna and Billfish Fishery Data Summary 2004-2005. Data Group, Australian Fisheries Management Authority, Canberra.

Murua, H. & F. Saborido-Rey, 2003. Female reproductive strategies of marine fish species of the North Atlantic. J. Northwest Atl. Fish. Sci. 33:23-31.

Nakamura, I. 1985. FAO Species Catalogue. Billfishes of the world. An annotated and illustrated catalogue of marlins, sailfishes, spearfishes, and swordfishes known to date. FAO Fisheries Synopsis No. 125, Vol. 5. Rome : FAO. 65 pp. 41 figs

Nakamura, I. 2001. Xiphiidae, Istiophoridae. pp. 3757-3764 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218.

Nishikawa, T., Ueyanagi, S. 1974. The distribution of the larvae of swordfish, Xiphias gladius, in the Indian and Pacific Oceans. In: R.S. Shomura, F. Williams (ed.), Proceedings of the International Billfish Symposium, part 2, pp. 261-264. Review and contributed papers.

Palko, R.J., Beardsley, G.L. & Richards, W.J. 1981. Synopsis of the biology of the swordfish Xiphias gladius Linnaeus. NOAA Tech Rept. NMFS Circ. FAO Fish. Synop. 127: 1–21 figs 1–12.

Pepperell, J. 2010. Fishes of the Open Ocean: A Natural History and Illustrated Guide. UNSW Press, 272 pp

Phillipps, W.J. 1932. Notes on new fishes from New Zealand. New Zealand Journal of Science and Technology 13(4): 226-234 figs 1-5 (described as Xiphias estara)

Randall, J.E., Allen, G.R. & Steene, R. 1990. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 507 pp. figs.

Reeb, C., Arcangeli, L. & Block, B. 2000. Structure and migration corridors in Pacific population of the swordfish (Xiphias gladius) as inferred through analyses of mitochondrial DNA. Mar. Biol. 136: 1123-1131.

Takahashi, M., H. Okumara, K. Yokawa, M. Okazaki. 2003. Swimming behaviour and migration of a swordfish recorded by an archival tag. Mar. Freshw. Res. 54: 527–534.

Videler JJ, Haydar D, Snoek R, Hoving H-JT, Szabo BG. 2016. Lubricating the swordfish head. Journal of Experimental Biology 219: 1953-1956; doi: 10.1242/jeb.139634

Ward, P. & Elscot, S. (2000) Broadbill Swordfish: Status of World Fisheries. Bureau of Rural Sciences, Canberra. Available at: http://adl.brs.gov.au/data/warehouse/brsShop/data/12908_intro-swordfishreport.pdf

WCPFC. 2008. Conservation and Management of Swordfish. CMM 2008-05.

Young, J., Drake, A., Brickhill, M., Farley, J. & Carter, T. 2003. Reproductive dynamics of broadbill swordfish, Xiphias gladius, in the domestic longline fishery off eastern Australia. Mar. Fresh. Res. 54:315-332.

Quick Facts


CAAB Code:37442001

Biology:'Warm-blooded'

Conservation:IUCN Least Concern

Depth:0-800 m

Fishing:Commercial, recreational species

Max Size:4.5 m; 600 kg

Species Image Gallery

Species Maps

CAAB distribution map