3 Fish biology and anatomy Биологија и анатомија на ... - UNDP
3 Fish biology and anatomy Биологија и анатомија на ... - UNDP
3 Fish biology and anatomy Биологија и анатомија на ... - UNDP
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102<br />
In Crucian carp the membrane lining<br />
the body cavity (the peritoneum) is light<br />
coloured, while in Prussian carp it is<br />
almost black.<br />
A Prussian carp can grow to a length of<br />
20-25 cm <strong>and</strong> a weight of some 250 g in<br />
five years. The species has a maximum<br />
length of 45 cm <strong>and</strong>, in favourable<br />
conditions, can reach a weight of 2-3 kg.<br />
Unlike the common carp Cyprinus carpio<br />
– there are no barbells.<br />
Biology<br />
The Prussian carp is a warm water fish,<br />
<strong>and</strong> thrives best in shallow lagoons <strong>and</strong><br />
estuaries (with a depth of just a few<br />
metres), shallow pools <strong>and</strong> lakes, <strong>and</strong><br />
slow-flowing rivers with muddy beds.<br />
The species is associated with dense<br />
vegetation <strong>and</strong> feeds mainly on benthic<br />
organisms. It grows rapidly, reproduces<br />
efficiently, <strong>and</strong> competes with native fishes<br />
for food <strong>and</strong> space. In some parts of<br />
central Europe it has affected the range of<br />
other indigenous <strong>and</strong> commercially more<br />
valuable fish species. The species is able<br />
to reproduce by gynogenesis, a process<br />
which only gives rise to new females. The<br />
milt of male fish is needed to initiate the<br />
development of the eggs, but once the<br />
embryos form, the males are excluded.<br />
The offspring produced are thus copies<br />
of the female. It can also tolerate waters<br />
with relatively low oxygen levels.<br />
Крајн<strong>и</strong>те ед<strong>и</strong>нечн<strong>и</strong> а<strong>на</strong>лн<strong>и</strong> <strong>и</strong> дорзалн<strong>и</strong><br />
зрац<strong>и</strong> се с<strong>и</strong>лно <strong>на</strong>забен<strong>и</strong>, <strong>и</strong>ма 37-52<br />
жабрен<strong>и</strong> лац<strong>и</strong>, а стран<strong>и</strong>ч<strong>на</strong>та л<strong>и</strong>н<strong>и</strong>ја<br />
е со 29-33 лушп<strong>и</strong>; слободн<strong>и</strong>те краев<strong>и</strong><br />
од грб<strong>на</strong>та перка се вдлаб<strong>на</strong>т<strong>и</strong> <strong>и</strong>л<strong>и</strong><br />
<strong>и</strong>справен<strong>и</strong>, а а<strong>на</strong>л<strong>на</strong>та перка е со 5½<br />
разгранет<strong>и</strong> зрац<strong>и</strong>.<br />
Кај златн<strong>и</strong>от карас мембра<strong>на</strong>та која<br />
ја обв<strong>и</strong>ткува стомач<strong>на</strong>та празн<strong>и</strong><strong>на</strong><br />
(пер<strong>и</strong>тонеумот) е бледо обое<strong>на</strong>, додека<br />
кај сребрен<strong>и</strong>от караш таа е целосно<br />
цр<strong>на</strong>. Карашот може да расте до<br />
голем<strong>и</strong><strong>на</strong> од 20-25 cm <strong>и</strong> да дост<strong>и</strong>гне<br />
теж<strong>и</strong><strong>на</strong> од околу 250 gr за пет год<strong>и</strong>н<strong>и</strong>.<br />
В<strong>и</strong>дот дост<strong>и</strong>гнува макс<strong>и</strong>мал<strong>на</strong> голем<strong>и</strong><strong>на</strong><br />
од 45 cm, а во поволн<strong>и</strong> услов<strong>и</strong> може да<br />
дост<strong>и</strong>гне теж<strong>и</strong><strong>на</strong> од 2-3 kg. За разл<strong>и</strong>ка<br />
од крапот Cyprinus carpio, овој в<strong>и</strong>д нема<br />
мустаќ<strong>и</strong>.<br />
<strong>Б<strong>и</strong>олог<strong>и</strong>ја</strong><br />
Карасот е р<strong>и</strong>ба која префер<strong>и</strong>ра топл<strong>и</strong><br />
вод<strong>и</strong>, а <strong>на</strong>јдобро опстојува во пл<strong>и</strong>тк<strong>и</strong><br />
лагун<strong>и</strong> <strong>и</strong> речн<strong>и</strong> уст<strong>и</strong>ја, пл<strong>и</strong>тк<strong>и</strong> бар<strong>и</strong> <strong>и</strong><br />
езера <strong>и</strong> бавн<strong>и</strong> рек<strong>и</strong> со т<strong>и</strong>њесто дно.<br />
Ж<strong>и</strong>вее <strong>на</strong> места со густа вегетац<strong>и</strong>ја, а<br />
главно се хран<strong>и</strong> со бентосн<strong>и</strong> форм<strong>и</strong>.<br />
Расте многу брзо, се размножува<br />
еф<strong>и</strong>касно, стапувајќ<strong>и</strong> во компет<strong>и</strong>ц<strong>и</strong>ја со<br />
пр<strong>и</strong>родн<strong>и</strong>те в<strong>и</strong>дов<strong>и</strong> за хра<strong>на</strong> <strong>и</strong> простор.<br />
Во неко<strong>и</strong> делов<strong>и</strong> од Централ<strong>на</strong> Европа<br />
<strong>и</strong>ма големо вл<strong>и</strong>јан<strong>и</strong>е врз друг<strong>и</strong>те<br />
пр<strong>и</strong>родн<strong>и</strong> <strong>и</strong> комерц<strong>и</strong>јално з<strong>на</strong>чајн<strong>и</strong><br />
в<strong>и</strong>дов<strong>и</strong> <strong>на</strong> р<strong>и</strong>ба. В<strong>и</strong>дот е способен да се<br />
размножува преку г<strong>и</strong>ногенеза, процес<br />
кој овозможува продукц<strong>и</strong>ја само <strong>на</strong><br />
нов<strong>и</strong> женск<strong>и</strong> ед<strong>и</strong>нк<strong>и</strong>. Млечот од машк<strong>и</strong>те<br />
ед<strong>и</strong>нк<strong>и</strong> е потребен да <strong>и</strong>н<strong>и</strong>ц<strong>и</strong>ра развој <strong>на</strong><br />
<strong>и</strong>кр<strong>и</strong>, но кога се форм<strong>и</strong>ра ембр<strong>и</strong>онот,<br />
хромозом<strong>и</strong>те од машк<strong>и</strong>те ед<strong>и</strong>нк<strong>и</strong> се<br />
<strong>и</strong>склучуваат. Потомството кое се создава<br />
е коп<strong>и</strong>ја <strong>на</strong> женката. Овој в<strong>и</strong>д <strong>и</strong>сто така<br />
може да толер<strong>и</strong>ра <strong>и</strong> релат<strong>и</strong>вно н<strong>и</strong>ск<strong>и</strong><br />
концентрац<strong>и</strong><strong>и</strong> <strong>на</strong> растворен к<strong>и</strong>слород.<br />
Rrezja e fundit e thjeshtë anale dhe ato<br />
kurrzore janë të dhëmbëzuara fort; 37-52<br />
gjembavelëzor; vija anësore me 29-33<br />
luspa; sipërfaqja e mysët kurrizore me<br />
skaje të lira ose të drejta; penda anale me<br />
5½ rreze të buta të degëzuara. Te krapi<br />
membrana që mbështjellë kavitetin e<br />
trupit (peritoneum) është lehtë e ngjyrosur,<br />
përderisa tek karasi prusian ajo është<br />
pothuajse e zezë. Karasi prusian mund<br />
të rritet deri në një gjatësi prej 20-25 cm<br />
dhe peshë afërsisht 250 g brenda pesë<br />
viteve. Specia arrin gjatësi maksimale<br />
prej 45 cm në kushte të volitshme, mund<br />
të arrijë peshë prej 2-3 kg. Ai mund të<br />
ngatërrohet me karasin e ri prusian i cili<br />
i përngjanë krapit të ri të artë (Carassius<br />
auratus auratus), meqë pendët e<br />
tyre fillimisht janë në ngjyrë ari. Duke u<br />
rritur kjo gjendje ndryshon duke marrë<br />
ngjyrën e argjendit. Për dallim nga krapi i<br />
zakonshëm Cyprinus carpio – tek ky nuk<br />
gjenden mustaqet.<br />
Biologjia<br />
Karasi prusian është peshk i ujërave të<br />
ngrohta, dhe më së miri zhvillohet në<br />
lagunat e cekëta dhe grykëderdhjet e<br />
gjera (me thellësi prej vetëm disa metra),<br />
pishina dhe liqene të cekëta dhe lumenj<br />
me rrjedhje të ngadaltë dhe me shtretër<br />
me baltë. Specia rritet mirë në bimësi<br />
të zhvilluar dhe ushqehet kryesisht me<br />
organizma fundor. Rritet shpejtë, riprodhohet<br />
me efikasitet, dhe garon me peshqit<br />
autokton për ushqim dhe hapësirë.<br />
Në disa pjesë të Evropës Qendrore ka<br />
ndikuar në një varg të specieve peshku<br />
të tjerë vendas të cilët janë komercialisht<br />
më të vlefshëm. Kjo specie është e aftë të<br />
riprodhohet me anë të gjinogjenezës, një<br />
proces në të cilin rritet numrin i femrave<br />
të reja.<br />
Οι τελευταίες οπίσθιες και ραχιαίες<br />
ακτίνες είναι έντονα οδοντωτές; 37-<br />
52 βράγχια; πλευρική γραμμή με 29-<br />
33 λέπια; απελευθερωμένη κόψη του<br />
ραχιαίου συνδέσμου ή ίσια; οπίσθιο<br />
πτερύγιο με 5 ½ συνδεόμενες ακτίνες.<br />
Στον χρυσαφί κυπρίνο η μεμβράνη που<br />
διαγραμμίζει την κοιλότητα του σώματος<br />
είναι ανοιχτόχρωμη, ενώ στην Πεταλούδα<br />
είναι σχεδόν μαύρη. Η Πεταλούδα μπορεί<br />
να μεγαλώσει σε μήκος 20-25 εκ. και<br />
σε βάρος 250 γρ. σε πέντε χρόνια. Το<br />
είδος έχει μέγιστο μήκος 45 εκ. και σε<br />
ιδανικές συνθήκες μπορεί να φτάσει σε<br />
βάρος τα 2-3 κιλά. Αντίθετα με τον κοινό<br />
κοινό κυπρίνο (Cyprinus carpio), δεν έχει<br />
μουστάκια.<br />
Βιολογία<br />
Η Πεταλούδα είναι ένα ψάρι ζεστών<br />
νερών και ακμάζει καλύτερα σε ρηχές<br />
λιμνοθάλασσες και εκβολές ποταμών<br />
(με βάθος μόνο μερικών μέτρων), σε<br />
ρηχές λιμνούλες και λίμνες, και σε<br />
ποταμούς ήπιας ροής με λασπώδη<br />
βυθό. Το είδος συνδέεται με την πυκνή<br />
υδρόβια βλάστηση και τρέφεται κυρίως<br />
με βενθικούς οργανισμούς. Μεγαλώνει<br />
γρήγορα, αναπαράγεται αποτελεσματικά<br />
και ανταγωνίζεται για φαγητό και χώρο<br />
με τα ντόπια είδη. Σε μερικά μέρη της<br />
κεντρικής Ευρώπης έχει επηρεάσει το<br />
εύρος των ιθαγενών ειδών και των πιο<br />
εμπορικά πολύτιμων ψαριών. Το είδος<br />
είναι ικανό να αναχαραχτεί με γυνογένεση,<br />
μια διαδικασία που παράγει μόνο νέα<br />
θηλυκά. Το σπέρμα του αρσενικού<br />
ψαριού χρειάζεται για την έναρξη της<br />
ανάπτυξης των αυγών, αλλά όταν τα<br />
έμβρυα σχηματίζουν τα χρωμοσώματα,<br />
αυτά των αρσενικών εξαιρούνται. Οι γόνοι<br />
που παράγονται είναι έτσι αντίγραφα των<br />
θηλυκών. Επίσης, μπορεί να ανεχθεί νερά<br />
με σχετικά χαμηλά επίπεδα οξυγόνου.