Kew Gardens - London - September 2008 (2952022283)

Rostrum (from

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

', meaning ''

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...

'') is a term used in

anatomy Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...

for a number of phylogenetically unrelated structures in different groups of animals. Nebalia

Invertebrates

* In

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, the rostrum is the forward extension of the

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

in front of the eyes. It is generally a rigid structure, but can be connected by a hinged joint, as seen in

Leptostraca Leptostraca (from the Greek words for ''thin'' and ''shell'') is an order of small, marine crustaceans. Its members, including the well-studied ''Nebalia'', occur throughout the world's oceans and are usually considered to be filter-feeders. It ...

. * Among

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s, the rostrum is the name for the piercing mouthparts of the order

Hemiptera Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, Reduviidae, assassin bugs, Cimex, bed bugs, and shield bugs. ...

as well as those of the

snow scorpionflies Boreidae, commonly called snow scorpionflies, or in the British Isles, snow fleas (no relation to the snow flea ''Hypogastrura nivicola'') are a very small family of scorpionflies, containing only around 30 species, all of which are boreal or h ...

, among many others. The long snout of

weevil Weevils are beetles belonging to the Taxonomic rank, superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and Herbivore, herbivorous. Approximately 97,000 species of weevils are known. They b ...

s is also called a rostrum. *

Gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

molluscs have a rostrum or

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...

. *

Cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

molluscs have hard beak-like mouthparts referred to as the rostrum. File:Washington DC Zoo - Macrobrachium rosenbergii 6.jpg, Crustacean: the rostrum of the shrimp ''

Macrobrachium rosenbergii ''Macrobrachium rosenbergii'', also known as the giant river prawn or giant freshwater prawn, is a commercially important species of Palaemonidae, palaemonid freshwater prawn. It is found throughout the tropical and subtropical areas of the Ind ...

'' is

serrated Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied p ...

along both edges. File:Gminatus australis with Beetle.jpg, Insect:

assassin bug The Reduviidae are a large cosmopolitan family of the order Hemiptera (true bugs). Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators: most other predatory Hemiptera are aquatic. The main example ...

piercing its prey with its rostrum File:Architeuthis beak.jpg, Cephalopod: the two-part beak of a

giant squid The giant squid (''Architeuthis dux'') is a species of deep-ocean dwelling squid in the family Architeuthidae. It can grow to a tremendous size, offering an example of abyssal gigantism: recent estimates put the maximum size at around Trace ...

File:Convolvulus hawk-moth (Agrius convolvuli) 2.jpg, Proboscis of hawk-moth (''

Agrius convolvuli ''Agrius convolvuli'', the convolvulus hawk-moth, is a large hawk-moth. It is common throughout Europe, Asia, Africa, Australia and New Zealand, partly as a migrant. In New Zealand, it is also known as the kumara moth, and in the Māori language ...

'')

Vertebrates

In mammals, the rostrum is that part of the

cranium The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

located in front of the

zygomatic arches In anatomy, the zygomatic arch, or cheek bone, is a part of the skull formed by the zygomatic process of the temporal bone (a bone extending forward from the side of the skull, over the opening of the ear) and the temporal process of the zygomati ...

, where it holds the teeth, palate, and nasal cavity. Additionally, the

corpus callosum The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental m ...

of the human brain has a nerve tract known as the rostrum. The beak or snout of a

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

may also be referred to as the rostrum. * Some cetaceans, including

toothed whales The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. Seventy-three species of t ...

such as

dolphin A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...

s and

beaked whales Beaked whales (systematic name Ziphiidae) are a family of cetaceans noted as being one of the least known groups of mammals because of their deep-sea habitat and apparent low abundance. Only three or four of the 24 species are reasonably well-kn ...

, have rostrums (beaks) which evolved from their jawbones. The narwhal possesses a large rostrum (tusk) which evolved from a protruding canine tooth. * Some

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

have permanently protruding rostrums which evolved from their upper jawbones.

Billfish The term billfish refers to a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than . Extant billfish include sailfish and marlin, which make up the family Istioph ...

(

marlin Marlins are fish from the family Istiophoridae, which includes about 10 species. A marlin has an elongated body, a spear-like snout or bill, and a long, rigid dorsal fin which extends forward to form a crest. Its common name is thought to deri ...

, swordfish and

sailfish The sailfish is one or two species of marine fish in the genus ''Istiophorus'', which belong to the family Istiophoridae ( marlins). They are predominantly blue to gray in colour and have a characteristically large dorsal fin known as the ...

) use rostrums (bills) to slash and stun prey.

Paddlefish Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elongla ...

goblin shark The goblin shark (''Mitsukurina owstoni'') is a rare species of deep-sea shark. Sometimes called a "living fossil", it is the only extant representative of the family Mitsukurinidae, a lineage some 125 million years old. This pink-skinned anima ...

s and

hammerhead shark The hammerhead sharks are a group of sharks that form the family Sphyrnidae, so named for the unusual and distinctive structure of their heads, which are flattened and laterally extended into a "hammer" shape called a cephalofoil. Most hammerhe ...

s have rostrums packed with

electroreceptor Electroreception and electrogenesis are the closely-related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes to stu ...

s which signal the presence of prey by detecting weak electrical fields.

Sawshark A sawshark or saw shark is a member of a shark order (Pristiophoriformes ) bearing a unique long, saw-like rostrum (snout or bill) edged with sharp teeth, which they use to slash and disable their prey. There are eight species within the Pristi ...

s and the critically endangered

sawfish Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish ...

have rostrums (saws) which are both electro-sensitive and used for slashing. The rostrums extend

ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

ly in front of the fish. In the case of hammerheads the rostrum (hammer) extends both ventrally and laterally (sideways). File:Istiophorus platypterus .jpg,

Sailfish The sailfish is one or two species of marine fish in the genus ''Istiophorus'', which belong to the family Istiophoridae ( marlins). They are predominantly blue to gray in colour and have a characteristically large dorsal fin known as the ...

, like all

billfish The term billfish refers to a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than . Extant billfish include sailfish and marlin, which make up the family Istioph ...

, have a rostrum (bill) which is an extension of their upper jawbone File:Paddlefish Polyodon spathula.jpg, The

paddlefish Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elongla ...

has a rostrum packed with

s File:Sawfish genova.jpg,

Sawfish Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish ...

have an electro-sensitive rostrum (saw) which is also used to slash at prey

References

Animal anatomy {{Animal-anatomy-stub

Invertebrates

Vertebrates

See also

References