Family MACROURIDAE


Common name: Grenadiers, Rattails, Whiptails

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Summary:
The family Macrouridae is a diverse and ecologically important group of deepwater cod-like fishes. Grenadiers or rattails usually live near the bottom on the continental slope, although a few species are bathypelagic or mesopelagic, while others are live on the outer continental shelf. Macrourids have a large head, a short trunk and a long tapering tail, which usually lacks a caudal fin. The first dorsal fin is usually high with the first rays spinous, the second dorsal fin is low, the pelvic fins are thoracic, and a chin barbel is usually present. Many species have an abdominal light organ containing luminous bacteria. Maximum length is 1.5 m.

Cite this page as:
Dianne J. Bray, 2012, Grenadiers , MACROURIDAE, in Fishes of Australia, accessed 25 May 2016, http://www.fishesofaustralia.net.au/home/family/264

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Family Taxonomy

A large family with more than 400 species in 32 genera. At least 106 species in 28 genera are known to occur in Australian waters, many of which were described in the past 10-15 years. Most Australian species are treated in Iwamoto & Williams (1999) and Iwamoto & Graham (2001).

Family Distribution

Although greandiers or whiptails are found in nearly every ocean from Arctic to Antarctic waters, including in the deep ocean basins, they are most numerous in deep tropical waters. Most species are benthic or benthopelagic, with a few bathypelagic and mesopelagic species. They live in depths of 200-4000m, some as deep as 6000m. Some species are very wide-ranging.

Family Description

Body with very long tapering tail. The head is usually large and variable in shape, usually with a pointed, protruding snout overhanging an inferior mouth. The eyes are usually large and a chin barbel is usually present. The two dorsal fins are separated by distinct gap. The first is high, triangular in shape with spinous rays. The second dorsal fin is long and low, extending to the end of the tail, and is continuous with the well-developed anal fin. The caudal fin absent, but a 'false' caudal fin may develop if the tail tip is nipped off. The pelvic fins, usually located below the pectoral-fin bases, are short-based with an elongate outermost ray and widely separated fin bases. Teeth are present in jaws, but absent from the palate. The scales usually have many spinules of various sizes and shapes, often distinctly arranged. The head scales are distinctly ridged and coarsely spinulated in many genera, and some have spiny scute-like scales on the tip of the snout. A light organ containing luminescent bacteria is often present on the ventral midline of the abdomen.

Family Size

From about 25 cm to more than 1.5 m, most less than 50 cm.

Family Feeding

Macrourids reportedly feed on other fishes, crustaceans, squids and echinoderms. They also scavenge on carrion that has drifted down from above. The few oceanic midwater species reportedly feed on other midwater fishes and squid.

Family Reproduction

Little is known of macrourid reproduction, early life history or biology. They lay relatively small pelagic eggs, 1-2 mm in diameter, which are thought to be spawned in large numbers near the bottom, and float upwards when released. Some larvae are thought to hatch near the thermocline and gradually descend towards the bottom as they develop and metamorphose. Little is known of larval development. Macrourid larvae are elongate, have a coiled gut and round eyes, and development is gradual with no specialized pelagic juvenile stage.

Family Commercial

As fisheries are established in greater depths throughout the world, macrourids are commercially fished or taken as bycatch in commercial fisheries. A few large species are commercially fished in the Atlantic and North Pacific. Macrourids are reported to have watery, tasteless flesh, and most are too small and uncommon to commercially imortant. Many species, however, are caught as bycatch in other fisheries and are used fresh or processed into fishmeal or fish paste.

Family Conservation

Not evaluated.

Family Remarks

Although many species have a ventral light organ on the abdomne that contains luminescent bacteria, the function of this luminescence is poorly understood. It may be involved in species recognition and breeding. All except a few bathypelagic species have a swim bladder and most are benthopelagic, hovering just above the bottom, often in head-down position; most with a chin barbel used to taste and explore the substrate to help find prey; the few mesopelagic species have no chin barbel, and their watery gelatinous flesh assists their buoyancy. Many grenadiers have special drumming muscles in their gas bladders, thought to help in finding a mate.

Family Biology

Many species have a ventral light organ containing luminescent bacteria. Although the function of the luminescence is poorly understood, it may be involved in species recognition and breeding. Most species are benthopelagic, hovering just above the bottom, often in head-down position, and all except a few bathypelagic species have a swim bladder. Most have a chin barbel used to taste and explore the substrate to help find prey. The few mesopelagic species have no chin barbel, and watery gelatinous flesh that assists their buoyancy.

Author

Dianne J. Bray

References


Bray, D.J., D.F. Hoese, J.R. Paxton & J.E. Gates. 2006. Macrouridae (pp. 581-607). In Beesley, P.L. & A. Wells. Zoological Catalogue of Australia. Volume 35. Fishes. CSIRO Publishing and ABRS.

Cohen, D.M., T. Inada, T. Iwamoto & N. Scialabba. 1990. FAO species catalogue. Vol. 10. Gadiform fishes of the world (order Gadiformes). An annotated and illustrated catalogue of cods, hakes, grenadiers and other gadiform fishes known to date. FAO (Food and Agriculture Organization of the United Nations) Fisheries Synopsis No. 125, v. 10: i-x + 1-442.

Iwamoto, T. 1990. Macrouridae, pp. 192-206. In Gon, O. & P.C. Heemstra (eds.) Fishes of the Southern Ocean. J.L.B. Smith Institute of Ichthyology, Grahamstown, South Africa: xviii, 462 pp. 12 leaves of plates.

Iwamoto, T. 1999. Order Gadiformes. In Carpenter, K.E. & V.H. Niem. Species identification guide for fisheries purposes. The living marine resources of the western central Pacific. Batoid fishes, chimeras and bony fishes part 1 (Elopidae to Linophrynidae). FAO, Rome

Iwamoto, T. & K.J. Graham. 2001. Grenadiers (Families Bathygadidae and Macrouridae, Gadiformes, Pisces) of New South Wales, Australia. Proceedings of the California Academy of Sciences 52(21): 407-509, 114 figs.

Iwamoto, T. & K.J. Graham. 2008. Two new Australian grenadiers of the Coelorinchus fasciatus species group (Macrouridae: Gadiformes: Teleostei). Proceedings of the California Academy of Sciences (Series 4) 59(5): 133-146.

Iwamoto, T. & P.J. McMillan. 2008. Family Macrouridae. In Gomon, M.F., D.J. Bray and R.H. Kuiter. (Eds.) Fishes of Australia's Southern Coast. New Holland Publishers. Melbourne, Australia. 1-928.

Iwamoto, T. & N.R. Merrett. 1997. Pisces Gadiformes: Taxonomy of grenadiers of the New Caledonian region, southwest Pacific. Memoires du Museum National d'Histoire Naturelle (N. S.) (Série A) Zoologie No. 176: 473-570.

Iwamoto, T. & A. Williams. 1999. Grenadiers (Pisces, Gadiformes) from the continental slope of western and northwestern Australia. Proceedings of the California Academy of Sciences 51(3): 105-243.

McMillan, P., T. Iwamoto, A. Stewart & P.J. Smith. 2012. A new species of grenadier, genus Macrourus (Teleostei, Gadiformes, Macrouridae) from the southern hemisphere and a revision of the genus. Zootaxa 3165: 1–24.

Merrett, N.R. & T. Iwamoto. 2000. Pisces Gadiformes: Grenadier fishes of the New Caledonian region, southwest Pacific Ocean. Taxonomy and distribution, with ecological notes. In Crosnier, R. (ed). Résultats des Campagnes MUSORSTOM, v. 21. Memoires du Museum National d'Histoire Naturelle (N. S.) (Série A) Zoologie No. 184: 723-781.

McMillan, P.J. & T. Iwamoto. 2009. Two new species of Coelorinchus (Teleostei, Gadiformes, Macrouridae ) from the Tasman Sea. Proceedings of the California Academy of Sciences (Series 4) 60(4): 39-51.

Nelson, J.S. 2006. Fishes of the world. John Wiley & Sons, Inc. Hoboken, New Jersey. 601 pp.

Sazonov, Yu.I., Yu.N. Shcherbachev & T. Iwamoto. 2003. The grenadier genus Mataeocephalus Berg, 1898 (Teleostei, Gadiformes, Macrouridae), with descriptions of two new species. Proc. Calif. Acad. Sci. 54(17): 279-301.

Sazonov, Yu.I. 1981. Idiolophorhynchus andriashevi gen. et sp. n. (Osteichthyes, Macrouridae) from the Australia-New Zealand region. Zool. Zh. 60(9): 1357-1363. [In Russian, English summ.]

Sazonov, Yu.I. & Yu.N. Shcherbachev. 1982. A preliminary review of grenadiers related to the genus Cetonurus Günther (Gadiformes, Macrouridae). Description of new taxa related to the genera Cetonurus Günther and Kumba Marshall. Voprosy Ikhtiol. 22(5): 707-721. [In Russian. English transl. in J. Ichthyol. 22(5):1-15.]

Shcherbachev, Yu.N., Yu.I. Sazonov & T. Iwamoto. 1992. Synopsis of the grenadier genus Kuronezumia (Pisces: Gadiformes: Macrouridae), with description of a new species. Proc. Calif. Acad. Sci. 48(3): 97-108.