Upload
mb21
View
582
Download
1
Tags:
Embed Size (px)
Citation preview
-
2
«ENDANGERED SPECIES»
IN SEVER DO VOUGA
3
Legenda: 1. Cedrim do Vouga 2. Couto Esteves 3. Dornelas 4. Paradela do Vouga 5. Pessegueiro do Vouga 6. Rocas do Vouga 7. Sever do Vouga 8. Silva Escura 9. Talhadas
4
«Petromyzon Marinus or Lampreys»
(sometimes also called lamprey
eels)
5
Lampreys
Are a family of jawless
fish, whose adults are
characterized by a toothed,
funnel-like sucking mouth.
Translated from a mixture of Latin
and Greek, lamprey means stone lickers
(lambere: to lick, and petra: stone).
6
In zoology, lampreys are sometimes
not considered to be true fish because of
their distinctive morphology
and physiology.
The lampreys are the basal group of
Vertebrata (hagfishes are actually not
vertebrates, but craniates).
7
Morphology
Adults physically resemble eels, in that they
have no scales, and can range anywhere from
13 to 100 centimeters (5 to 40 inches) long.
Lacking paired fins, adult lampreys have large
eyes, one nostril on the top of the head, and
seven gill pores on each side of the head.
8
Curiosity
Lampreys are called
"nine-eyed eels" (i.e., per
side) from a counting of
their seven external gill
slits on a side with one
eye and the nostril. A
German word for
lamprey is Neunauge,
which means "nine-eye".
9
What do they eat?
They feed on prey as adults by
attaching their mouthparts to the target
animal's body, then using their teeth to
cut through surface tissues until they
reach blood and body fluid.
10
Where do they live?
Lampreys live mostly in coastal and
fresh waters, although some species,
travel significant distances in the open
ocean, as evidenced by their lack of
reproductive isolation between
populations.
They are found in most temperate
regions except those in Africa.
11
Uses: «Portuguese lamprey rice»
They were highly appreciated by
ancient Romans. Their taste is much meatier
than that of most true fish. King Henry I of
England is said to have died from eating "a
surfeit of lampreys". On March 4th,
1953, Queen Elizabeth's coronation pie was
made by the Royal Air Force using lampreys.
12
13
Especially in southwestern Europe
(Portugal, Spain, and France), larger lampreys
are still a highly prized delicacy. Lampreys
are also consumed in Sweden, Finland,
Russia, the Baltic countries and South Korea.
In Britain, lampreys are commonly used
as bait, normally as dead bait.
Pike, perch and chub all can be caught on
lampreys. Frozen lampreys can be bought
from most bait and tackle shops.
14
DAMS and ENDAGERED SPECIES
Rivers possess a delicate ecology that depends on
a regular cycle of disturbance within certain
tolerances. Dams disrupt this ecology.
There are several types of dams.
Check dams
Diversion dams
Flood control dams
Hydroelectric dams
15
- Check dams prevent flooding of small areas.
- Diversion dams divert river water to irrigate
crops. Large dams may be built for flood control or
electrical generation, or both.
- Flood control dams are often earth dams--
made of huge mounds of clay, sand, gravel, and
rock--but often made of concrete.
- Hydroelectric dams are concrete marvels of
engineering. This section will examine mostly the
large dams: flood control and hydroelectric dams.
16
DAM in SEVER DO VOUGA
17
-