Polypterus senegalus Cuvier(多鰭魚科)
俗名多鰭魚,英文名Senegal bichir
原產于非洲塞(sai)內加爾(er)。
中型淡水(shui)魚類。體長(chang)在300-400毫(hao)米,體重300-600克。體延長(chang),稍(shao)側(ce)扁。背鰭(qi)(qi)(qi)(qi)由一列尖棘狀小(xiao)(xiao)鰭(qi)(qi)(qi)(qi)組成,每1小(xiao)(xiao)鰭(qi)(qi)(qi)(qi)由1鰭(qi)(qi)(qi)(qi)軸骨(gu)支持著,并(bing)有(you)一前(qian)后扁平的(de)(de)硬鰭(qi)(qi)(qi)(qi)條。臀鰭(qi)(qi)(qi)(qi)較(jiao)(jiao)短,位于體的(de)(de)后下部。胸鰭(qi)(qi)(qi)(qi)基(ji)部呈肉(rou)(rou)質葉(xie)。腹鰭(qi)(qi)(qi)(qi)肉(rou)(rou)質葉(xie)較(jiao)(jiao)胸鰭(qi)(qi)(qi)(qi)小(xiao)(xiao),距胸鰭(qi)(qi)(qi)(qi)較(jiao)(jiao)遠。尾鰭(qi)(qi)(qi)(qi)歪(wai)形。體被菱形的(de)(de)厚硬鱗(lin)。鰾有(you)輔助呼吸功能。
洪水期(qi)在沼澤中產卵。仔魚具外鰓。生殖季(ji)節雄魚的臀鰭變(bian)大。遠古時代遺留下來的魚類(lei)之一,人稱“活化石魚”。肉味頗(po)美,可供食(shi)用;由(you)于其體型特異,供人們作觀(guan)賞用。
原生(sheng)金(jin)恐(kong)(kong)龍(long)(long)(long)(long)分布(bu)于東(dong)非、西非和中非,分布(bu)廣(guang)泛(fan),產量(liang)極大,由于有8個背鰭(qi),也被稱(cheng)(cheng)為九節龍(long)(long)(long)(long)。金(jin)恐(kong)(kong)龍(long)(long)(long)(long)屬于小(xiao)型恐(kong)(kong)龍(long)(long)(long)(long),體長30厘(li)(li)米(mi),性情溫和,適(shi)于混養。成(cheng)年后的(de)金(jin)恐(kong)(kong)龍(long)(long)(long)(long)身(shen)體不(bu)乏粗(cu)壯,而且其實(shi)它們是瓦(wa)灰色(se)的(de);之所以會有“金(jin)恐(kong)(kong)龍(long)(long)(long)(long)”這個稱(cheng)(cheng)呼(hu),是因(yin)為10厘(li)(li)米(mi)左右的(de)幼魚鱗色(se)很(hen)淺(qian),略帶(dai)反光,且肚(du)皮微(wei)微(wei)泛(fan)出(chu)淡黃色(se)。因(yin)為產量(liang)很(hen)大,金(jin)恐(kong)(kong)龍(long)(long)(long)(long)中陸續出(chu)現了紅眼白子、黑眼白子等(deng)變異(yi)個體,都是很(hen)有價值的(de)收藏;甚至還有背鰭(qi)擴(kuo)大化變異(yi)形成(cheng)的(de)“仙女(nv)恐(kong)(kong)龍(long)(long)(long)(long)”,更(geng)是別有一番(fan)風味。
恐龍魚(yu)一類較(jiao)具有(you)觀賞性(xing)的(de)(de)(de)泳姿在(zai)金恐龍這里也得(de)到了充分表現:由于它(ta)們的(de)(de)(de)結構原始,體(ti)表被覆(fu)的(de)(de)(de)硬鱗又(you)限(xian)制了身(shen)體(ti)的(de)(de)(de)靈(ling)活性(xing),所以顯然它(ta)們不太擅長用“S”形搖擺的(de)(de)(de)方式輕松游(you)泳。恐龍魚(yu)的(de)(de)(de)運動(dong)方式,是將(jiang)所有(you)的(de)(de)(de)動(dong)力任務(wu)都(dou)推(tui)給胸(xiong)鰭,通過胸(xiong)鰭的(de)(de)(de)快速擺動(dong)來“帶領”身(shen)體(ti)前(qian)移(yi),而(er)整條(tiao)身(shen)軀就像一根棒槌被拖著,只在(zai)轉彎(wan)的(de)(de)(de)時候(hou)才發生形變(bian)。看來胸(xiong)鰭基部的(de)(de)(de)肌(ji)肉(rou)果然不是白長的(de)(de)(de),如(ru)此(ci)長時間負(fu)荷(he)高強度(du)的(de)(de)(de)跑步(bu)任務(wu),真是肌(ji)肉(rou)中的(de)(de)(de)戰斗機。
恐(kong)(kong)龍(long)(long)魚的嘴型根據(ju)生態(tai)位大致分(fen)成三個類(lei)群,金(jin)恐(kong)(kong)龍(long)(long)是其中最(zui)嫩(nen)弱(ruo)嬌瘦的第一型,上(shang)顎(e)長于下顎(e),習慣在水(shui)底搜尋小魚或(huo)有機物殘渣(zha);它(ta)們的飼養(yang)較為簡(jian)單,基本(ben)上(shang)屬于新手上(shang)路的級別,喜歡微酸(suan)至中性的水(shui)環境,pH 6~7,溫度22°C~28°C。對食(shi)物也(ye)并不挑剔,各類(lei)活餌以(yi)及干(gan)蝦(xia)都可以(yi)接受。但金(jin)恐(kong)(kong)龍(long)(long)魚類(lei)善(shan)于跳(tiao)躍,飼養(yang)時注意水(shui)箱(xiang)要(yao)加(jia)蓋。