薄皮虼蚤屬

薄皮虼蚤屬（學名：_ Leptodora _）為薄皮虼蚤科動物唯一的一个屬。過往本屬干焦透明薄皮虼蚤（學名：_ Leptodora kindtii _）一个物種，一直到二空空九年本屬的第二个物種予人發現。這兩个物種佇咧對比其他雙甲下綱物種的來講會較大，最近透明佮通光，是一類掠食性的物種。本屬物種上長可長至二十一  mm（空九八三英寸）， 有兩枝咧用，作泅水的觸角，以及一隻複眼。跤骨通用作捕碰巧路過的被跤亞綱物種。

透明薄皮虼蚤看北半球溫帶的湖泊中，真有可能是枝角目物種當中唯一捌予人報章報導過的已經描述生物；而且 _ L . richardi _ 現時只見著俄羅斯遠東地區的烏龍江流域，就算日本就想講佇其國內分佈的物種亦是 _ L . richardi _。 For most of the year , _ Leptodora _ reproduces 單性生殖，with males only appearing late in the season , to produce winter eggs which hatch the following spring . _ Leptodora _ is the only genus in its family , theLeptodoridae, and suborder ,Haplopoda.

形態描述

薄皮虼蚤屬物種的成體是北美洲原生浮游枝角目物種當中體型上大的；到底有偌大，各種的報告間無盡相𫝛，但母性成體普遍可長到十二  mm（空曉四七英寸）長，部份報告聲稱可長到二十一  mm（空九八三英寸）長。遮的動物的身體約有百分之九十八是若透明的，避免去予魚仔獵食。

Lilljeborg notes :

> Das Weibchen ist in so hohem Grade durchsichtig , in wahrem Sinne »wasserhell» , dass oft nur die Bewegungen ihr Dasein in dem Wasser verrathen . Bei auffallendem Sonnenlicht wird gewöhnlich der Schatten früher als das Thier selbst entdeckt . > >

> The female is transparent to such a high degree , literally " as clear as water " , that her presence is often only given away by her movements . In bright sunlight , the shadow is normally seen before the animal itself . > >

The male is similarly transparent . The abdomen is elongated , but the carapace is small and only covers the brood pouch .

胸坎的六對附肢形成一个「飼籃仔」，用掠的物件。 The second 觸角 are used for swimming , while the first antennae are 痕跡器官 in females but elongated in males , where they are used in 有性生湠 . There is a single large 複眼 which takes up much of the animal's head . It comprises around 五百 facets , which are spherically arranged , and the whole eye is movable by up to 十 ° in any direction .

分佈

透明薄皮虼蚤分佈佇北半球溫帶的湖泊中，看過北美洲、亞洲、歐洲佮非洲。佇彼北美洲，其分佈範圍南至德克薩斯州佮俄克拉荷馬州；佇中國大陸分佈浙江、江蘇、安徽、江西、湖北、吉林、烏龍江、雲南、內蒙古等地，主要生湠佇大中型湖泊的水區、也出現佇沿岸佮小型湖泊佮積水較深的水池仔內底。佇歐洲、北非部份地區、阿拉伯半島北部佮亞洲喜馬拉雅山脈以北地區也有分佈。

生態佮行為

透明薄皮虼蚤是一種貪婪的掠食者，會當控制其偏愛獵物的數量，一般攏是石頭仔（_ Daphnia _）、 _ Bosmina _ , _ Ceriodaphnia _ , _ Diaphanosoma _ , _ Diaptomus _ , _ Polyphemus _ 佮劍水虼蚤屬（_ Cyclops _）這等各屬物種的幼體。It seems to encounter its prey by chance , with contact initiating a 反射 ( 生意學 ) , in which the 腹肚 is brought forward to close the feeding basket . In many cases , the prey escapes this haphazard response . Juvenile _ Daphnia _ are slower than adults to respond to the predator's attack , and are therefore more likely to be caught .

The most important predators of _ Leptodora _ are fishes , including 白鰱屬，perch , ziege and 歐白魚 .

In 琵琶湖，日本，_ L . kindtii _ is 寄生 by the 線蟲動物門 _ Raphidascaris biwakoensis _ , a parasite of 魚 .

性命週期

母的薄皮虼蚤屬動物會當干焦透過單性生殖就會當生卵，而且每隔十二點鐘就閣會當閣後一搭卵子。遮的卵孵了後進入幼體階段，身長差不多二公釐（空空七九英寸）。 了後𪜶咧生做蟲仔進前，閣愛經歷六个 instar，到完全生長，體長增加到六公釐（空空二四英寸）。 事實上，對孵化到成蟲階段，需要三工到六工，視著愛孵的時陣環境。佇一年的真大多數的時陣，薄皮虼蚤屬動物的生湠攏干焦靠單性生湠，所生產的卵攏為母性，並無雄性的卵子。到甲秋季，透過單性生殖的雄性卵子開始出現；雄性佮雌性進行有性生殖才變甲會用得。遮的透過交配行為誕下的受精卵會佇𪜶越冬的所在地沉到上底，直到後一年才會孵化，成做 nauplius-like larvae .。

Related taxa

_ Leptodora _ is so distinct from other cladocerans that some authors have suggested grouping all other cladocerans into a 演化支 called " Eucladocera " , with _ Leptodora _ as its 姊妹仔 . It is now believed , however , that _ Leptodora _ is sister to Onychopoda , being the only genus in the familyLeptodoridaeand the subclassHaplopoda. Features which separate it from other families include its large size , the lack of branchial appendages ( 鰓 s ) on its legs , the reduction of the carapace , and the fact that the winter eggs hatch as nauplii .

Taxonomic history

_ Leptodora kindtii _ is " probably the only cladoceran ever described in a newspaper " . The German microscopist Gustav Woldemar Focke organised a 學術研討會 in 無萊梅 in 一千八百四十四 together with the pharmacist Georg Christian Kindt . He studied the fauna of the ditches surrounding the city ( the _ Bremer Stadtgraben _ ) and displayed live specimens at the meeting . During the meeting , he also published a description of the species in the _ Weser-Zeitung _ on Sunday September 二十二 , 一千八百四十四 , placing the species in the genus _ Polyphemus _ . However , this description was ignored by the scientific community , and Wilhelm Lilljeborg described the species in 一千八百六十一 with the name _ Leptodora hyalina _ . The 異名 was not noticed until Simon Albrecht Poppe informed Lilljeborg of it in 一千八百八十九 , and Lilljeborg corrected the error in his 一千九百專著 .

二空空九年，Korovchinsky 頭一擺為本屬的第二个物種 _ Leptodora richardii _ 作出描述：這个物種採樣自烏龍江盆地的湖泊，包括博隆湖。

異名

現時下列的組合攏予人看做透明賊仔（_ Leptodora kindtii _）的異名：

• _ Polyphemus kindti _ Focke , 一千八百四十四
• _ Hyalosoma dux _ Wagner , 一千八百六十八
• _ Leptodora angusta _ Sars , 一千八百九十
• _ Leptodora hyalina _ Lilljeborg , 一千八百六十一
• _ Leptodora pellucida _ Joseph , 一千八百八十二

語源

The name _ Leptodora _ is from the 希臘語 words _ leptos _ and _ dora _ , collectively meaning thin-skinned . The 種加詞 _ kindtii _ is presumed to refer to G . C . Kindt , who worked closely with Focke . The alternative spelling _ kindti _ is sometimes encountered , but is no longer considered correct under the 國際動物號名法規 . The epithet _ hyalina _ , used by Lilljeborg , is from the Greek _ ὕαλος _ , and means glassy .

下屬物種

本屬包括以下的物種：

• _ Leptodora kindti _ ( Focke , 一百八十四四 )
• _ Leptodora richardi _ Korovchinsky , 二千空九

外部連結

• _ Leptodora kindtii _ . Missouri State University . 二千空六鼻八 [二千空二十二孵一孵二十] .（原始內容存檔佇兩千空一十二分三鋪四）（英語）.
• Creature of the Month : _ Leptodora kindtii _ . Zooplankton-online . net . 二千空五孵七 [二千空一十三孵十九] .（原始內容存檔佇兩千空六鋪十九）（英語）.
• _ Leptodora kindtii _ swimming ( QuickTime ) . University of New Hampshire . 二千空二十二二（英語）.
• _ Leptodora kindtii _ swimming and bending . University of New Hampshire . [二千空一十三孵十九] .（原始的內容 ( QuickTime ) 存檔佇二千空六鋪九九九五）（英語）.