All you need to know-uneed2know.eu
Go Up

Top 101 Prehistoric creatures living today

Add to favourite
Back
Region/Country
Type of animal

Sea Lamprey–The silent Invader

Sponsored links

Sponsored links

    The sea lamprey (Petromyzon marinus)  has been around since the existence of dinosaurs. Like the shark and the crocodile, sea lampreys have barely changed over thousands of millennia.

Sea lamprey,prehistoric living fossil, jawless fish, parasite, hematophagous feeding

    Acording to some discoveries  (http://www.scienceinafrica.com/ (7)) ,scientists from the University of the Witwatersrand and the University of Chicago have discovered a 360 million-year-old lamprey, from Witteberg Group rocks near Grahamstown, in the Eastern Cape.
In the 22 June 2006 issue of Nature, Mee-mann Chang and colleagues reported on a fossil lamprey from the same Early Cretaceous lagerstätten that have yielded feathered dinosaurs, in the Yixian Formation of Inner Mongolia, laid down around some 120 million years ago.(http://en.wikipedia.org/wiki/Lamprey#Fossil_record)


Sea lamprey,prehistoric living fossil, jawless fish, parasite, hematophagous feeding

    Some researchers have classified lampreys as the sole surviving representatives of the Linnean class Cephalaspidomorphi, and fossil evidence now suggests lampreys and cephalaspids acquired their shared characters by convergent evolution.
Also called cyclostomes meaning “circular mouths”, they are part of the Agnathans  family.  This is the largest and the most pushy lamprey out of all the rest. Once it’s done feasting at sea, the adults start to migrate towards rivers. This is usually set off by the temperature alterations. This migration process happens during spring.
Other common names: great sea lampreys, lamprey eels.



Characteristics

    It has no bones, no jaws just pure cartilage. Brown or gray are the colors you will see on its back, and brown or white on its belly.  And adult sea lamprey can measure 90 cm long and can weight 2.5 kg.  Their mouths are round and so are their teeth are arranged in rows. They have big eyes, no scales what so ever and single findfolds, both dorsal and ventral. Some of the sea lamprey are true parasites, others however don’t fit into this category.

There are 4 species of native lampreys which are:

•    Silver lamprey
•    Chestnut lamprey
•    Northern brook lamprey ( unlike the parasitic ones mention above, this was it not)
•    American brook lamprey( not parasitic either)



Location
•    Great Lakes
•    Atlantic Ocean
•    Western Mediterranean Sea



Diet
    The sea lamprey aims for freshwater fish such as salmon, trout or herrings as well as invertebrates. It feeds by linking on to the prey with its mouth sucker. They have an aggressive temper and they also feed aggressively.  



Reproduction

    The process occurs in freshwaters during the spring season. While they spawn, the feeding ceases to happen. This is because the male requires full energy to reproduce. The fertilization is an external procedure. The amount of eggs that are laid by the female is somewhere between 35.00 to 100.000.  The male prepares a cozy spot for the female to deposit the eggs and after the larvae( also called Ammocoetes ) hatch, they feed on algae and bacteria. A curious fact is that they don’t look anything like the adult lamprey. They are completely blind and even their fins are different. However as they develop, they take on the adult resemblance. Only when they reach the adult stage, they begin to migrate.



Threats

    The sea lamprey population can be affected by pollution and constructions that are evolving near the rivers. People have been cautious and have taken measures to prevent these invaders from ruining other fish populations.



Interesting facts
•    They are considered a finger-licking dish in some parts of Europe
•    The sea lamprey is classified as the largest cyclostome in Europe
•    Did you know that once the spawning process is over, the lampreys die? This occurs because their bodies start to deteriorate, not to mention the fact that they are vulnerable to  bacteria.
•    A major problem is that the Great Lakes have been invaded by these aquatic vertebrates. These sneaky invaders have found an opening through the Welland Canal. The whitefish and burbot are a few examples of fish population that were almost ravaged by the sea lamprey back in 1940. So in order to repent further disturbances of the ecosystem,  people have been making efforts to keep their spreading under control by using pesticides or dams in the rivers.
•    After several years in freshwater habitats, the larvae undergo a metamorphosis that allows young postmetamorphic lampreys to migrate to the sea or lakes and start the hematophagous feeding.
•    Wondering how you can distinguish the adults from the young ones? Simply through their color. The adults are brown or grey and their coloration lightens as they prepare to spawn, and the youngsters are more of a greenish-brown shade.
•    Lampreys provide valuable insight into the evolution of the adaptive immune system, as they possess a convergently evolved adaptive immunity with cells that function like the T cells and B cells seen in higher vertebrates.
•    They also go by the name of  “stone suckers”
•    Like Megalodon - the prehistoric ancestor of today shark - sea lamprey fossils are very rare; because cartilage does not fossilize as readily as bone. The first fossil lampreys were originally found in Early Carboniferous limestones, marine sediments laid down more than 300 million years ago in North America.

Sponsored links



Sources:
http://en.wikipedia.org/wiki/Sea_lamprey (1)
http://www.arkive.org/sea-lamprey/petromyzon-marinus/ (2)
http://marinebio.org/species.asp?id=542 (3)
http://www.iisgcp.org/exoticsp/lamprey.htm (4)
http://www.softschools.com/facts/animals/sea_lamprey_facts/252/ (5)
http://pigout666.wix.com/all-about-lamprey#!__lamprey-fun-facts (6)
http://www.scienceinafrica.com/old/index.php?q=2007/february/lamprey.htm (7)

Pictures
http://upload.wikimedia.org/wikipedia/commons/d/d0/Boca_de_lamprea.1_-_Aquarium_Finisterrae.JPG (1)
http://msutoday.msu.edu/_/img/assets/2012/sea-lamprey-mouth.jpg (2)
http://gallery.usgs.gov/images/11_08_2013/u85Cs21rrm_11_08_2013/large/Sea_lamprey_parasitic_mouth_-_A._Miehls__USGS.JPG (3)
http://lampreysurveys.files.wordpress.com/2014/02/sea-lamprey.jpg (4)
http://upload.wikimedia.org/wikipedia/commons/9/9b/Lamprey_anatomy.png (5)
https://www.flickr.com/photos/noaa_glerl/8741578394/lightbox/ (6)
http://blog.syracuse.com/outdoors/2008/05/051208LAMP1mjg.JPG (7)
23 November 2014, 15:00 Sea lamprey, prehistoric, living fossil, jawless fish, parasite2389
Share

Facebook comments (0)

u2know comments (0)

Add a comment

I have account on u2know
E-mail
Password
Remember me Forgot password?
Comment
Notify me of follow up comments via e-mail