Male frogs are typically smaller than the females. Their average life span is two to four years in the wild, but up to nine years in captivity. Tadpoles are dark brown with tan tails. Lampreys are an amazing group of ancient fish species which first appeared around million years ago.
This means they evolved millions of years before the dinosaurs roamed the earth. There are about 39 species of lamprey currently described plus some additional landlocked populations and varieties.
In general, lamprey are one of three different life history types and are a combination of non-parasitic and parasitic species. Non-parasitic lamprey feed on organic material and detritus in the water column. Parasitic lamprey attach to other fish species to feed on their blood and tissues. Most, 22 of the 39 species, are non-parasitic and spend their entire lives in freshwater. The remainder are either parasitic spending their whole life in freshwater or, parasitic and anadromous.
Anadromous parasitic lampreys grow in freshwater before migrating to the sea where they feed parasitically and then migrate back to freshwater to spawn. The Cowichan Lake lamprey Entosphenus macrostomus is a freshwater parasitic lamprey species. It has a worm or eel-like shape with two distinct dorsal fins and a small tail.
It is a slender fish reaching a maximum length of about mm. When they are getting ready to spawn they shrink in length and their dorsal fins overlap. Unlike many other fish species, when lampreys are getting ready to spawn you can tell the difference between males and females. Females develop fleshy folds on either side of their cloaca and an upturned tail. The males have a downturned tail and no fleshy folds.
These seven gill pores are located one after another behind the eye. There are several characteristics which are normally used to identify lamprey. Many of these are based on morphometrics or measurements, of or between various body parts like width of the eye or, distance between the eye and the snout.
Other identifying characteristics include body colour and the number and type of teeth. Some distinguishing characteristics of this species are the large mouth, called and oral disc and a large eye. This species also has unique dentition. For example, these teeth are called inner laterals.
Each lateral tooth has cusps and together they always occur in a cusp pattern. At the same time, the Sea Otter is the largest member of its family, the mustelids, which includes River Otters, weasels, badgers, wolverines and martens. It may come to land to flee from predators if needed, but the rest of its time is spent in the ocean. It varies in colour from rust to black. Unlike seals and sea lions, the Sea Otter has little body fat to help it survive in the cold ocean water. Instead, it has both guard hairs and a warm undercoat that trap bubbles of air to help insulate it.
The otter is often seen at the surface grooming; in fact, it is pushing air to the roots of its fur. Mollusks are invertebrates, meaning they have no bones. They are cold-blooded, like all invertebrates, and have blue, copper-based blood. The octopus is soft-bodied, but it has a very small shell made of two plates in its head and a powerful, parrot-like beak.
The Giant Pacific Octopus is the largest species of octopus in the world. Specimens have weighed as much as kg and measured 9. Studies determined, though, that they are indeed different. While the Western Chorus Frog might have slightly shorter legs than the Boreal Chorus Frog, and that their respective calls have different structures, genetics have proven this.
Chorus Frogs are about the size of large grape, about 2. They are pear-shaped, with a large body compared to their pointed snout. Their smooth although a bit granular skin varies in colour from green-grey to brownish. They are two of our smallest frogs, but best ways to tell them apart from other frogs is by the three dark stripes down their backs, which can be broken into blotches, by their white upper lip, and by the dark line that runs through each eye.
Their belly is generally yellow-white to light green. Males are slightly smaller than females, but the surest way to tell sexes apart is by the fact that only males call and can inflate their yellow vocal sacs. Adults tend to live only for one year, but some have lived as many as three years.
Their tadpoles the life stage between the egg and the adult are grey or brown. Their body is round with a clear tail. The Common Raven Corvus corax is one of the heaviest passerine birds and the largest of all the songbirds.
It is easily recognizable because of its size between 54 and 67 centimetres long, with a wingspan of to cm, and weighing between 0. It has a ruff of feathers on the throat, which are called 'hackles', and a wide, robust bill.
When in flight, it has a wedge-shaped tail, with longer feathers in the middle. While females may be a bit smaller, both sexes are very similar. The size of an adult raven may also vary according to its habitat, as subspecies from colder areas are often larger. A raven may live up to 21 years in the wild, making it one of the species with the longest lifespan in all passerine birds. Both birds are from the same genus order of passerine birds, corvid family —like jays, magpies and nutcrackers, Corvus genus and have a similar colouring.
But the American Crow is smaller with a wingspan of about 75 cm and has a fan-shaped tail when in flight with no longer feathers. Their cries are different: the raven produces a low croaking sound, while the crow has a higher pitched cawing cry. While adult ravens tend to live alone or in pairs, crows are more often observed in larger groups. The Atlantic Cod Gadus morhua is a medium to large saltwater fish: generally averaging two to three kilograms in weight and about 65 to centimetres in length, the largest cod on record weighed about kg and was more than cm long!
Individuals living closer to shore tend to be smaller than their offshore relatives, but male and female cod are not different in size, wherever they live. The Atlantic Cod shares some of its physical features with the two other species of its genus, or group of species, named Gadus. The Pacific Cod and Alaska Pollock also have three rounded dorsal fins and two anal fins. They also have small pelvic fins right under their gills, and barbels or whiskers on their chins.
Both Pacific and Atlantic Cod have a white line on each side of their bodies from the gills to their tails, or pectoral fins. This line is actually a sensory organ that helps fish detect vibrations in the water. The colour of an Atlantic Cod is often darker on its top than on its belly, which is silver, white or cream-coloured. In rocky areas, a cod may be a darker brown colour. Cod are often mottled, or have a lot of darker blotches or spots.
It can weigh up to 63, kilograms and measure up to 16 metres. Females tend to be a bit larger than males — measuring, on average, one metre longer. Its head makes up about a fourth of its body length, and its mouth is characterized by its arched, or highly curved, jaw. Its skin is otherwise smooth and black, but some individuals have white patches on their bellies and chin.
It has large, triangular flippers, or pectoral fins. Its tail, also called flukes or caudal fins, is broad six m wide from tip to tip! Unlike most other large whales, it has no dorsal fin. For a variety of reasons, including its rarity, scientists know very little about this rather large animal. For example, there is little data on the longevity of Right Whales, but photo identification on living whales and the analysis of ear bones and eyes on dead individuals can be used to estimate age.
It is believed that they live at least 70 years, maybe even over years, since closely related species can live as long. Unique characteristics. The Right Whale has a bit of an unusual name. Its name in French is more straightforward; baleine noire, the black whale. The American Eel Anguilla rostrata is a fascinating migratory fish with a very complex life cycle.
Like salmon, it lives both in freshwater and saltwater. It is born in saltwater and migrating to freshwater to grow and mature before returning to saltwater to spawn and die. The American Eel can live as long as 50 years. It is a long, slender fish that can grow longer than one metre in length and 7.
Males tend to be smaller than females, reaching a size of about 0. With its small pectoral fins right behind its gills, absence of pelvic fins, long dorsal and ventral fins and the thin coat of mucus on its tiny scales, the adult eel slightly resembles a slimy snake but are in fact true fish.
Adult eels vary in coloration, from olive green and brown to greenish-yellow, with a light gray or white belly. Females are lighter in colour than males.
Large females turn dark grey or silver when they mature. The American Eel is the only representative of its genus or group of related species in North America, but it does have a close relative which shares the same spawning area: the European Eel. Both have similar lifecycles but different distributions in freshwater systems except in Iceland, where both and hybrids of both species can be found.
The American Lobster Homarus americanus is a marine invertebrate which inhabits our Atlantic coastal waters. As an invertebrate, it lacks bones, but it does have an external shell, or exoskeleton, making it an arthropod like spiders and insects.
Its body is divided in two parts: the cephalothorax its head and body and its abdomen, or tail. On its head, the lobster has eyes that are very sensitive to movement and light, which help it to spot predators and prey, but are unable to see colours and clear images. It also has three pairs of antennae, a large one and two smaller ones, which are its main sensory organs and act a bit like our nose and fingers.
Around its mouth are small appendages called maxillipeds and mandibles which help direct food to the mouth and chew. Spring migration occurs in Washington between late March and mid-May. The Herring Gull is currently the most widespread large gull. It experienced a sharp decline during the 19th Century, mostly due to feather- and egg-hunting.
The dramatic recovery and range expansion of the Herring Gull during the 20th Century is due to a number of factors, including protection from feather-hunting and egg-harvesting.
Increased commercial fishing has reduced populations of large predatory fish, allowing an increase in numbers of small and medium-sized fish. A reduction of marine mammal populations has also helped to ease pressure on the small and medium fish. Increased numbers of garbage dumps following the spread of human populations along coastlines may aid in juvenile survival.
Populations in the historic range have recovered, and new areas have been colonized as Herring Gulls expand their range down the Atlantic Coast. A concurrent range expansion has not been seen on the West Coast. In the mids and s, numbers leveled off, perhaps due to closure and modification of garbage dumps, as well as the reduction of even the small and medium fish stocks.
On the West Coast, the status of the Herring Gull is confused by its hybridization with the Glaucous-winged Gull in Alaska, and by the fact that the Thayer's Gull was considered a subspecies of Herring Gull from The numbers of Herring Gulls breeding in British Columbia appear to be increasing. In winter, Herring Gulls can commonly be seen in small numbers roosting with other large gulls in all regions of the state, except for the mountains, in marine and fresh water habitats. In eastern Washington, they are common in these waters from October to April, and absent the rest of the year.
In western Washington, they are common during migration from February to mid-April, and again in October. If you find the information on BirdWeb useful, please consider supporting Seattle Audubon. Support Seattle Audubon. Herring Gull Larus argentatus. Divorcees can be seen as less attractive to first time daters, often being left single and alone for a few nesting seasons. Seagulls are one of the few birds in the world that can drink fresh and salt water.
They have a special gland near their eye that removes the salt from their system. Gulls are strong communicators, signalling one another with specific calls and even body movements. Gulls are omnivores and will eat fish, eggs, insects or molluscs. Latin: Larus marinus.
Latin: Stercorarius skua. Latin: Larus glaucoides. Latin: Larus fuscus. Latin: Fulmarus glacialis. Latin: Morus bassanus. Latin: Stercorarius pomarinus. Latin: Larus delawarensis. Latin: Larus schistisagus. Latin: Stercorarius maccormicki. Latin: Larus thayeri. Latin: Larus michahellis. Membership benefits include one year of Audubon magazine and the latest on birds and their habitats.
Your support helps secure a future for birds at risk. Our email newsletter shares the latest programs and initiatives. Large, abundant, and widespread, the Herring Gull is among the most familiar members of its family, especially in the northeast. It has been extending its range toward the south along the Atlantic Coast in recent decades. In the west, where there are several similar large gulls, no such range expansion seems to be taking place.
Photo gallery. Feeding Behavior Opportunistic. Eggs 3, sometimes , rarely 4. Young May leave nest a day or two after hatching, remain in immediate area.
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