Whales in the Mysticeti suborder have baleen plates that serve as a filter-feeding system, while marine mammals in the Odontoceti suborder—which includes dolphins and porpoises as well as whales—have teeth. Different species of whales vary drastically in terms of both size and weight. Baleen whales in the Mysticeti suborder are generally larger than those of the Odontoceti suborder. The Mysticeti group includes the blue whale Balaenoptera musculus —the largest animal ever to live on the planet.
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March Learn how and when to remove this template message The two parvorders, baleen whales Mysticeti and toothed whales Odontocetiare thought to have diverged around thirty-four million years ago. Baleen whales have bristles made of keratin instead of teeth. The bristles filter krill and other small invertebrates from seawater.
Grey whales feed on bottom-dwelling mollusks. Rorqual family balaenopterids use throat pleats to expand their mouths to take in food and sieve out the water.
Most mysticetes prefer the food-rich colder waters of the Northern and Southern Hemispheres, migrating to the Equator to give birth. During this process, they are capable of fasting for several months, relying on their fat reserves.
The parvorder of Odontocetes — the toothed whales — include sperm whales, beaked whales, killer whales, dolphins and porpoises. Generally the teeth are designed for catching fish, squid or other marine invertebratesnot for chewing them, so prey is swallowed whole.
Teeth are shaped like cones dolphins and sperm whalesspades porpoisespegs belugastusks narwhals or variable beaked whale males. Female beaked whales' teeth are hidden in the gums and are not visible, and most male beaked whales have only two short tusks. A few toothed whales, such as some killer whalesfeed on mammals, such as pinnipeds and other whales.
Toothed whales have well-developed senses — their eyesight and hearing are adapted for both air and water, and they have advanced sonar capabilities using their melon.
Their hearing is so well-adapted for both air and water that some blind specimens can survive. Some species, such as sperm whales, are well adapted for diving to great depths.
Several species of toothed whales show sexual dimorphismin which the males differ from the females, usually for purposes of sexual display or aggression. Anatomy[ edit ] Dolphin anatomy Cetacean bodies are generally similar to that of fish, which can be attributed to their lifestyle and the habitat conditions.
Their body is well-adapted to their habitat, although they share essential characteristics with other higher mammals Eutheria. Almost all have a dorsal fin on their backs that can take on many forms depending on the species. A few species, such as the beluga whalelack them.
Both the flipper and the fin are for stabilization and steering in the water. The male genitals and mammary glands of females are sunken into the body.
In larger species, it can reach a thickness up to half a meter 1. Sexual dimorphism evolved in many toothed whales. Sperm whales, narwhalsmany members of the beaked whale family, several species of the porpoise family, killer whales, pilot whaleseastern spinner dolphins and northern right whale dolphins show this characteristic.
The fluke is set horizontally on the body, unlike fish, which have vertical tails. Hind legs are not present in cetaceans, nor are any other external body attachments such as a pinna and hair.
Their nostril s make up the blowholewith one in toothed whales and two in baleen whales. The nostrils are located on top of the head above the eyes so that the rest of the body can remain submerged while surfacing for air.
The back of the skull is significantly shortened and deformed. By shifting the nostrils to the top of the head, the nasal passages extend perpendicularly through the skull.
The braincase is concentrated through the nasal passage to the front and is correspondingly higher, with individual cranial bones that overlap. In toothed whales, connective tissue exists in the melon as a head buckle.
This is filled with air sacs and fat that aid in buoyancy and biosonar. The sperm whale has a particularly pronounced melon; this is called the spermaceti organ and contains the eponymous spermacetihence the name "sperm whale".
Even the long tusk of the narwhal is a vice-formed tooth. In many toothed whales, the depression in their skull is due to the formation of a large melon and multiple, asymmetric air bags. Other cetaceans have fused neck vertebrae and are unable to turn their head at all.
The baleen of baleen whales consists of long, fibrous strands of keratin.Whale sounds are used by whales for different kinds of communication.. The mechanisms used to produce sound vary from one family of cetaceans to another. Marine mammals, such as whales, dolphins, and porpoises, are much more dependent on sound for communication and sensation than are land mammals, because other senses are of .
The Order Cetacea consists of three suborders: the Mysticeti and Odontoceti (living) and the Archaeoceti (extinct).
The similarity between the living suborders is the result of convergence, and the Archaeoceti are not ancestral to the other two. Comparison of the principal characters distinguishing. All Living Things, in Seven Kingdoms. Note: This page contains an image, involving human anatomy, that some may regard as offensive or inappropriate.
They are divided into two subgroups, the Odontoceti (the toothed whales, including dolphins and porpoises) and the Mysticeti (the baleen whales), formerly suborders Subphylum: Vertebrata. comparison of the suborders Mysticeti (baleen whales) and Odontoceti (toothed whales).
Due to their extreme phylogenetic position within Odontoceti and relatively distant evolutionary relationship to delphinids (Milinkovich et al., ; Berta and Sumich, ; Geisler and Sanders, ). The primary difference between the two suborders, Mysticeti and Odontoceti, has to do with the whale’s feeding hardware.
Whales in the Mysticeti suborder have baleen plates that serve as a.