''Ballerus ballerus'', also known as the zope or the blue bream, is a species of
cyprinid fish native to
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...
.
Description
''Ballerus ballerus'' is one of the more streamlined
bream
Bream ( ) are species of freshwater and marine fish belonging to a variety of genera including '' Abramis'' (e.g., ''A. brama'', the common bream), '' Acanthopagrus'', ''Argyrops'', '' Blicca'', '' Brama'', '' Chilotilapia'', ''Etelis'', '' L ...
s, with a more laterally compressed body (especially towards the tail) and an upturned mouth.
[ The eye is small][ It has small scales and the lateral line consists of 67-75 scales. It is a pale silvery colour with either pale yellowish or colourless fins. They are normally 25–35 cm in length but occasionally can be up to 40 cm.][
]
Distribution
''Ballerus ballerus'' is found in the large lowland rivers draining to the Baltic Sea
The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain.
The sea stretches from 53°N to 66°N latitude and ...
, although it is not found in northern Sweden and Finland north of 62°N; the Weser
The Weser () is a river of Lower Saxony in north-west Germany. It begins at Hannoversch Münden through the confluence of the Werra and Fulda. It passes through the Hanseatic city of Bremen. Its mouth is further north against the ports o ...
and Elbe
The Elbe (; cs, Labe ; nds, Ilv or ''Elv''; Upper and dsb, Łobjo) is one of the major rivers of Central Europe. It rises in the Giant Mountains of the northern Czech Republic before traversing much of Bohemia (western half of the Czech Re ...
draining into the North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea, epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the ...
; the Black Sea
The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Rom ...
; the Don
Don, don or DON and variants may refer to:
Places
*County Donegal, Ireland, Chapman code DON
*Don (river), a river in European Russia
*Don River (disambiguation), several other rivers with the name
*Don, Benin, a town in Benin
*Don, Dang, a vill ...
draining into the Sea of Azov; and the Volga
The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catchm ...
and Ural
Ural may refer to:
*Ural (region), in Russia and Kazakhstan
*Ural Mountains, in Russia and Kazakhstan
*Ural (river), in Russia and Kazakhstan
* Ual (tool), a mortar tool used by the Bodo people of India
*Ural Federal District, in Russia
*Ural econ ...
which drain into the Caspian Sea
The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...
, although it is rare in the Ural River. Its range spans from the Netherlands in the west to Russia and Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
in the east.[
]
Habitat and ecology
''Ballerus ballerus'' is occurs in large lowland rivers and eutrophic
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplan ...
lakes[ where it feeds on plankton which it catches close to the surface.][ It spawns in Spring, once the ice has thawed, in shallow reedy bays onto the vegetation and the young fish stay in these areas although the adults move into open water to feed.][ Spawning has been recorded on gravel in areas of moderate current.][ This species lives for over 10 years and it breeds for the first time at 3–4 years when they have attained a standard length of 150mm. Spawning is initiated when the water temperature reaches 10 °C and usually lasts for only 1–2 weeks. The females spawn once a year while the males often defend spawning territories along the shoreline. It is known in some areas to migrate long distances to find suitable areas to spawn in. In some regions it will venture into the fresher parts of seas to find food.][
]
Zope software
The Python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (pro ...
-based application server Zope
Zope is a family of free and open-source web application servers written in Python, and their associated online community. Zope stands for "Z Object Publishing Environment", and was the first system using the now common object publishing methodol ...
is not named after this species; it is an acronym for "Z Object Published Environment". However, Zope3 was renamed "Bluebream", an alternative vernacular name for ''Ballerus ballerus''.
References
*
{{Taxonbar, from=Q220398
Ballerus
Cyprinid fish of Europe
Fish described in 1758
Taxa named by Carl Linnaeus