Skip to main content

Alewife

Alosa pseudoharengus
The Alewife is a member of the herring family that was originally found off of the Atlantic Coast. Though they are still exist in that range, over the last fifty years they have become an invasive species in the Great Lakes.

In the 1950s, Alewives used the Welland Canal in Ontario to get around Niagara Falls and enter the Great Lakes. Around that same time, Sea Lamprey also invaded, killing off many of the large prey species that would have normally consumed the Alewives. Lack of predation allowed the species to spread, and they are now most abundant in Lake Michigan and in Lake Huron.

Though they are still abundant in the Great Lakes, the population is more in check than it once was. This is due to the introduction of predator species like stocked Trout and Salmon. Unfortunately, the Alewives still vie for food (mostly zooplankton) with other fish, and have negatively affected other populations because of that competition.

Atlantic Alewives are anadromous, a term that means the fish live at sea, but come into freshwater to spawn. Great Lakes Alewives obviously live their entire lives in freshwater, though they spawn in more shallow areas, depositing up to 12,000 eggs! The larvae hatch after only a week, and the fish can live 6 to 7 years.
IUCN Status : Not Listed
Location : North America
Size : Length up to 6in (15cm)
Classification : Phylum : Chordata -- Class : Actinopterygii -- Order : Clupeiformes
Family : Clupeidae -- Genus : Alosa -- Species : A. pseudoharengus
Labels:

Comments

Post a Comment

Popular posts from this blog

Burmese Peacock

Polyplectron bicalcaratum Burmese Peacocks are also referred to as Grey Peacock-Pheasants, which is probably a more apt name, as they are not actually Peacocks... though they do belong to the same family. At any rate, they share some physical resemblances to Peacocks- most notably the eyes on their tail feathers. Burmese Peacocks are the national birds of Myanmar, which was called Burma until 1989, though some still refer to it as such. The birds live in several other Southeast Asian countries as well, and are divided into four subspecies. The species as a whole is listed as being of Least Concern , because they have a large range and population size. It unfortunately appears that they may be declining in number, but it is a slow descent that does not yet meet the vulnerability thresholds. The birds are listed under CITES Appendix II, because they can be kept in captivity and grabbing individuals from the wild could become problematic for the species. IUCN Stat...
3 comments
Read more

Bornean Orangutan

The Bornean Orangutan is one of two extant Orangutan species in the world. It is the third largest primate (after Gorillas) and is the largest primarily tree-dwelling animal in the world. Males are substantially larger than females, and average at around 165lbs. Bornean Orangutans are largely solitary. A handful might live within a small range but they will seldom interact with one another. Males and females only meet up to breed, which happens only once every several years. A young Orangutan will stay with it's mother for about five years, and the females tend to go about eight years between births. That is the longest interim period of any animal! Sadly, the Bornean Orangutans are in a lot of trouble. They need large forests in order to thrive, and deforestation and habitat degradation has left many homeless. They are also hunted for meat and for traditional medicines. Conservation areas are being established to help these guys in the wild, and it is believed that there are a...
59 comments
Read more

Four!

For anyone who was counting, yesterday was our birthday-- four years! Four years filled with animals from A to Z, more than 1,100 of them! I can't thank my readers enough, it's been wonderful! And in celebration of that milestone... I'm taking a break. Hopefully not forever, but for a little bit at least. In the mean time I plan on getting a new layout out, along with some updates to some of the older articles. I'll post updates here and on the Facebook page, I'm also brainstorming some new animal-related projects, so keep an eye out! Thanks again for four awesome years!
18 comments
Read more