Clupeiformes

(vertebrate zoology) An order of teleost fishes in the subclass Actinopterygii, generally having a silvery, compressed body.

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(Herrings)

Class: Actinopterygii

Order: Clupeiformes

Number of families: 5

Evolution and systematics

Fishes in the order Clupeiformes are teleosts, a group of fishes characterized evolutionarily by the presence of true bone forming their skeletons and by specific bone structures in the tail and skull. Teleosts arose during the early Mesozoic era (approximately 200 million years ago). Four subsequent radiations gave rise to the current major groups of fishes, with one of these radiations producing the Clupeomorpha. A major evolutionary feature that distinguishes clupeomorphs is the extension of the gas bladder into the brain case so that it contacts the inner ear, and thereby increasing the hearing ability of the fish. Modern Clupeiformes also possess other evolutionary advances over their closest ancestors: a modified joint in the jaw caused by fusion of the angular to the articular and a reduction of the caudal skeleton.

Two suborders, Clupeoidei and Denticipitoidei, are recognized in the Clupeiformes. The Clupeiodei includes the families Chirocentridae (wolf herrings; 1 genus, 2 species), Clupeidae (herrings, menhadens, pilchards, sardines, shads, and sprats; 5 subfamilies, 56 genera, 214 species), Engraulidae (anchovies; 2 subfamilies, 16 genera, 145 species), and Pristigasteridae (sawbelly herrings; 2 subfamilies, 9 genera, 36 species). The Denticipitoidei includes the family Denticipitidae (denticle herring; 1 genus, 1 species).

Physical characteristics

Clupeoids are small fusiform (tapering toward each end) fishes with streamlined bodies that facilitate fast swimming in open water. They have dark shading on their backs and bright silvery sides. Except for the head, their bodies are completely covered in large scales. Most clupeoids lack a lateral line, and only in the deticipitoid herring does this line extend along the body. The fins of clupeoids lack spines. A single dorsal fin is located near the middle of the body, and the tail is forked. Many clupeoids have a row of scutes, modified scales that usually have sharp points towards the rear, along the medial line of the belly. The smallest cluepoid is the Sanaga pygmy herring (Thrattidion noctivagus), measuring only 0.83 in (2.1 cm) in standard length; male wolf herrings (Chirocentrus spp.) are the largest herring, attaining standard lengths of 39 in (100 cm).

Distribution

Clupeiformes are widely distributed worldwide between 70°N to 60°S latitude. They primarily live in oceans, but some species inhabit coastal margins and fresh water for at least a portion of their lives.

Habitat

Nearly all Clupeiformes are open-water, pelagic species. Four-fifths of all species are marine, with habitats ranging from nearshore littoral zones to nearly 100 mi (160 km) offshore. Many are found near the surface at times but often move to deeper waters during the day. Some Clupeiformes live in inland waters or are anadromous, moving inland to spawn. These species utilize bays, estuaries, marshes, rivers, and freshwater streams as habitats. Landlocked populations have formed as shads, alewives, and herrings moved into lakes or rivers and became trapped between dams.

Behavior

Clupeiformes are perhaps best recognized for the large schools they form. Schools may include hundreds or thousands of individuals ranging from the young to adults, but individuals in a school are usually of similar size. Schooling is a form of organization in which behavior is synchronized; large numbers of fish may swim parallel to each other in the same direction with fairly uniform spacing. These synchronized aggregations are believed to confer swimming efficiency and, most importantly, to enable fishes to avoid or deter predators. Clupeiformes also congregate in smaller, less-organized shoals, particularly during spawning seasons. In addition to schooling, many Clupeiformes undertake some type of migration. Some clupeoid fishes are anadromous, migrating from the ocean to streams and rivers for spawning. They also may migrate inshore or latitudinally on a seasonal basis. Many clupeoids migrate in the water column on a diel basis, staying at deep depths during the day and moving to shallow depths at night.

Feeding ecology and diet

Most Clupeiformes filter feed by straining water through their long and numerous gill rakers. They consume plankton, particularly small crustaceans and the larval stages of larger crustaceans and fishes. Some herrings visually locate and target food particles. Clupeoid fishes are important prey for larger fishes, seabirds, and marine mammals.

Reproductive biology

Clupeiformes produce large numbers of offspring, either through a single seasonal spawning event or by spawning in seasonal peaks throughout the year. Most Clupeiformes spawn in shoals by broadcasting large numbers of small, buoyant eggs in waters near the surface. The eggs and larvae drift passively in currents as they develop. Herrings, on the other hand, produce demersal eggs that sink to the bottom, where they often adhere to the substrate until they hatch. After hatching, larvae become pelagic.

Conservation status

Two Clupeiformes are listed as Endangered by the IUCN: the Alabama shad (Alosa alabamae) and the Laotian shad (Tenualosa thibaudeaui). The Alabama shad is found in the northern portion of the Gulf of Mexico, from the Mississippi delta eastward to the Choctawhatchee River in Florida. It also occurs in inland rivers from Iowa to Arkansas and eastward to West Virginia. The Laotian shad occurs in the Mekong River basin, including inland waters of Thailand, Laos, and Cambodia. Most Clupeiformes are not threatened by severe population disruptions, but populations do show natural variability due to fluctuations in reproductive success. This natural variability is exacerbated by fishing pressure and global climate patterns.

Significance to humans

Clupeiformes are some of the most economically important fishes in the world's oceans. They have been widely exploited throughout human history, primarily for food but also as a source of oil, fertilizer, and animal feed. Herring fishing was one of the earliest occupations of coastal peoples, as first described in England in a chronicle that dates back to A.D. 709. The first commercial fishing establishment opened in Heligoland, a small island in the North Sea off the coast of Germany, in 1425.

Clupeiformes continue to constitute a large portion of world's commercial fisheries. Although 186 species are exploited by pelagic fisheries worldwide, 50% of the total landings in 1997 were represented by only seven species. Among these seven, four are Clupeiformes: the anchoveta (Engraulis ringens), Atlantic herring (Clupea harengus), Japanese pilchard (Sardinops melanostictus), and South American pilchard (Sardinops sagax). Herrings and anchovies constitute approximately 25% of the total fisheries harvest worldwide.

In addition to being heavily utilized by humans, Clupeiformes are an important component of the broader marine ecosystem. They serve as food items for larger predatory fishes, sea birds, and marine mammals. Thus, clupeoids sustain other organisms of importance to humans through ecosystem interactions.

Species accounts

Resources

Laws, Edward A. El Niño and the Peruvian Anchovy Fishery. Sausalito, CA: University Science Books, 1997.

Lecointre, G., and G. Nelson. "Clupeomorpha, Sister-Group of Ostariophysi." In Interrelationships of Fishes, edited by Melanie L. J. Stiassney, Lynne R. Parenti, and G. David Johnson. San Diego: Academic Press, 1996.

Petitgas, P., D. Reid, P. Carrera, M. Iglesias, S. Georgakarakos, B. Liorzou, and J. Masse. "On the Relation Between Schools, Clusters of Schools, and Abundance in Pelagic Fish Stocks." ICES Journal of Marine Science 58(2001): 1,150–1,160.

Whitehead, P. J. P. "Clupeoid Fishes of the World (Suborder Clupeoidei). An Annotated and Illustrated Catalogue of the Herrings, Sardines, Pilchards, Sprats, Shads, Anchovies, and Wolf-Herrings. Part 1—Chirocentridae, Clupeidae, and Pristigasteridae." FAO Fisheries Synopsis 125, no. 7(1985): 303.

Whitehead, P. J. P, G. J. Nelson, and T. Wongratana. "Clupeoid Fishes of the World (Suborder Clupeoidei). An Annotated and Illustrated Catalogue of the Herrings, Sardines, Pilchards, Sprats, Shads, Anchovies, and Wolf-Herrings." Part 2—Engraulidae." FAO Fisheries Synopsis 125, no. 7 (1988): 274.

Menhaden Resource Council. 1901 N. Fort Myer Drive, Suite 700, Arlington, VA 22209 USA. Phone: (703) 796-1793. E-mail: resource@menhaden.org Web site:

FAO Fisheries Department. (13 Nov. 2002)

FishBase. 8 Aug. 2002 (13 Nov. 2002).

[Article by: Katherine E. Mills, MS]

An order of teleost fishes of the subclass Actinopterygii that includes the herrings, sardines, anchovies, and their allies. The Recent clupeiforms are classified in 2 suborders, 3 (by some authorities as many as 6) families, 71 genera, and about 300 species.

The Clupeiformes are generalized teleosts. They are mostly silvery and compressed. A distinctive feature is the extension of the cephalic canal system onto the operculum; the lateral line is undeveloped on the trunk except in Denticeps. They lack fin spines, adipose fin, and gular plate. The middle of the belly often bears one or a series of strong scutes. The pelvic fin is abdominal in position, free from the shoulder girdle, and the pectoral fin is placed low on the side. The cycloid scales are usually thin and loosely attached. The upper jaw is bordered by premaxillae and maxillae, but the dentition is usually feeble.

Clupeiform fishes have left a rich fossil record, especially from the Upper Cretaceous to the early Tertiary, but appeared first in the Upper Jurassic. Some herrings and a few anchovies live in lowland rivers and lakes, and others such as the shad and alewife enter rivers to reproduce; but the majority of clupeiforms occur in bays or shore waters of tropical, temperate, or even northern seas, where they commonly make up enormous schools. None inhabits deep water. Most feed on plankton or other minute organisms. Thus they are efficient converters from the base of the food chain to fish flesh.

Some of the great fisheries of the world are based on the conversion of plankton by clupeiform fishes: the tremendous anchovy fishery off western South America; the California fisheries for anchovy and (until depleted) Pacific sardine; the menhaden fisheries of the western Atlantic; and the herring and sardine fisheries of northern seas. The catch is processed variously into oil, fertilizer, or fish meal or is prepared directly for human consumption. See also Actinopterygii.

Clupeiformes
Alosa fallax
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Clupeiformes
Families
Denticipitidae (denticle herring) Engraulidae (anchovies) Pristigasteridae (pristigasterids) Chirocentridae (wolf herring) Clupeidae (herrings)

Clupeiformes is the order of ray-finned fish that includes the herring family, Clupeidae, and the anchovy family, Engraulidae.

Clupeiformes are physostomes, which means that the gas bladder has a pneumatic duct connecting it to the gut.

The order includes about 300 species in five families.

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