全國中小學科展

動物學

Relationship between sexual deprived Drosophila, NPF, and the following behaviors

研究指出,公果蠅在求偶的過程中若被母果蠅拒絕,腦中的神經傳導蛋白NPF(neuropeptide F)會隨之下降,並提升其對酒精食物的攝取量。 我們的研究結果顯示求偶被拒的公果蠅是在「攝食酒精」後才對酒精成癮,而非在求偶被拒之後馬上去攝食酒精。而且,「求偶被拒」的公果蠅除了飲酒行為,也會提升其再求偶慾望。另外,我們利用Gal4-UAS系統調控了公果蠅腦中NPF神經的活性,發現公果蠅的NPF神經活性被抑制時,會出現與求偶被拒的公果蠅類似的行為。 最後,我們使用了NPF的螢光蛋白的抗體來標定NPF神經活性被激發以及抑制時腦中NPF的含量變化。透過這個結果,我們可以確定腦中NPF量的變化可以控制公果蠅對酒精的趨性、求偶慾望以及對酒精的攝食量。

以魚類耳石探討A.MAMORATA的生長和迴游特性

鱸鰻(Anguilla marmorata)曾經是台灣的保育類動物,雖然於2009年解除其保育類身分,但對於其生活史目前所知仍然非常有限,相關論文也很少。本研究欲藉由鱸鰻耳石上出現的年輪、日周輪以及微量元素之分析,來重建鰻魚的生長及洄游環境史。我們利用台灣大學漁業科學研究所採自菲律賓的野生鱸鰻和海南島的養殖鱸鰻進行分析,並且和已經發表的日本鰻(A. japonica) 文獻比對,以期歸納出鱸鰻的生活史以及棲地利用的特性。本研究的耳石測量在台灣大學漁業科學研究所進行,魚類耳石鍶鈣比則利用中央研究院地球科學研究所的電子微探儀(EPMA) 進行分析。結果發現鱸鰻自海中孵化後約莫經過130天會回到陸地的淡水環境成長,這與日本鰻回到陸地鹹淡水環境成長的特性有很大差別。這項發現對今後鱸鰻保育工作的環境管理措施,具有參考價值。

Gannet Investigation: Survivng an Unnatural Disaster

For a unique marine bird, so magnificent and accessible to the public, the Australasian Gannet (Morus serrator) colony found at Cape Kidnappers, 紐西蘭, significantly lacks research. Knowledge of gannet behaviour and how humans could best sustain a relationship with them remains unstudied. M. serrator are colonial monogamous breeders and produce a single chick each breeding season (Ismar, S.M.H. 2013). With the same mate over breeding seasons, pairs work cooperatively sharing the energy input into a single chick. Such parental care leads to highly territorial behaviour (McMeekan, C. P. & Wodzicki, K. A. 1946). This suggests more dominant gannets would claim larger territories to have a greater distance between nests of other birds, to increase the survival of their offspring. With a land-based colony this means the gannets are at risk from land and airborne predators, suggesting more dominant birds will claim territories in the central area as it offers greater safety from predator pressures (Minias, P. 2014). It was hypothesised that birds in the centre will have a greater distance between their nests and have a smaller height compared to those around the periphery of the Plateau Colony. The distances between nests and the heights of nests were recorded in the centre and around the periphery of the colony to determine if there was a correlation between the variables. It was found that centre nests had a greater distance between them and were of a smaller nest height when compared to those around the periphery. Anthropogenic influences from tourism and conservation has the potential to change the evolutionary trajectory of managed populations. This colony is protected by predator control programs. Altering this significant selection pressure has the potential to change the nesting behaviour of this species. Monitoring annual nesting distribution patterns and colony numbers over time, may enable informed development of more sustainable ecotourism and protection of the colony. This investigation provides baseline data to support further research on this colony.

螂吞虎嚥-探討嗅覺及味覺刺激對蜚蠊口器、唾腺及砂囊的影響

本研究以不同濃度各種溶液作為嗅覺與味覺刺激,探討人體與蜚蠊的辨識率與口器反應,發現蜚蠊口器的嗅覺受器極為敏感,大致呈現劑量效應(dose response)趨勢,且可偵測人體無法辨識之揮發性極低的物質,且具熱量之營養物質可增強口器的反射行為。此外,利用記錄組織電位變化的方式,我們發現餵食蔗糖溶液時,蜚蠊唾腺放電反應減弱,推測蔗糖會抑制唾腺分泌水樣唾液,避免稀釋酵素濃度影響消化分解;餵食麩胺酸及醋酸溶液時,唾腺放電反應增強,推測其會引發唾腺分泌水樣唾液,稀釋過高濃度的溶液。而餵食蔗糖溶液時,蜚蠊砂囊放電反應減弱,推測蔗糖會抑制砂囊肌肉收縮;餵食麩胺酸溶液時,蜚蠊砂囊放電則增加,推測麩胺酸會增加砂囊肌肉收縮,以利磨碎食物。

Investigating the Effect of Coloured Light on the Behaviour and Learning of Lymnae stagnalis

Lymnae stagnalis (pond snail) is emerging as a preferable invertebrate model in understanding neurological mechanisms because of its simple nervous system. A three-cell network mediates behaviours such as aerial respiration and research has shown that small, subtle changes occurring across the network might result in a disruption of natural behaviour (Lukowiak et al. 1995). It is also known that Lymnae features a more developed eye than other molluscs and studies have shown that various wavelengths of light can activate photoreceptors producing distinct electrophysiological responses (Sakakibara et al. 2004). However, no studies have looked beyond the electrophysiological response. The purpose of this project was to determine if coloured light would firstly, elicit a behavioural response as observed in its movement and secondly, affect learning and memory through the operant conditioning of its aerial respiration.

「孓」戰關鍵―台灣淡水渦蟲捕食蚊幼蟲機制及其黏液探討

虎紋三角渦蟲(Girardia tigrina)是台灣本土常見的渦蟲,常用於再生之研究。然而其黏液功能與成分以及捕食蚊幼蟲機制皆尚未清楚。本研究中,從解剖顯微鏡觀察得知渦蟲爬行時分泌的黏液能將蚊幼蟲纏住,且發現渦蟲偏好從蚊幼蟲腹部末端及肛進行攻擊,並於體外行物理機制初步消化後,將蚊幼蟲組織以咽運動產生的負壓吸入體內,再行化學分解。以Congo Red、CBR250及PAS染色,發現渦蟲黏液中具有多醣、蛋白質及醣蛋白,以SDS-PAGE分離渦蟲黏液蛋白後,用銀染法分析發現渦蟲黏液包含多種蛋白質,主要為蛋白質單體15kDa,以蛋白質N端定序及LC MS/MS交叉比對分析得知渦蟲黏液中可能含有titin、calcium-binding protein等蛋白質,相關實驗還在進行中。我們也發現渦蟲在有無蚊幼蟲環境不影響其黏液蛋白分泌量,然而黏液蛋白成分組成是否有差異,需再繼續研究。本研究結果可能對應用生物防治法抑制病媒蚊有所助益。

Novel holdfast marking behavior found in Seahorse

棘海馬 (Hippocampus spinosissimus) 經飼養觀察首次發現排放標示物行為。標示物標記偏好的棲枝,為海洋珊瑚礁魚類中類似的標示的新發現行為。觀察棘海馬會由泄殖腔孔排放一種白色的標示物,其成分鏡檢證明與棘海馬的排遺無關,且其更容易在水中漂流並黏附在棲枝上。棘海馬利用嗅覺幫助尋找含標示物的棲枝 (卡方值 : 24.183, P<0.001)。棘海馬不會傾向攀附有其他海馬標示物的棲枝,無論相同性別間或異性間,均未達顯著水準。標示物中有效成分為水溶性物質,其效能在室溫下可維持約7天,且冷藏可延長其標示效能。經由解剖觀察,證實標示物的分泌器官為泄殖腔中的生殖腺,但生殖腺切片中證明標示物分泌與棘海馬繁殖無關。

美洲蟑螂可分泌警告物質的證實與相關研究

社會性昆蟲已被證實可產生警告物質(disperation-inducing or alarm substances),對同種其他個體具有警告、驅離的效果。本研究發現美洲蟑螂(Periplaneta americana)雖不屬於真社會性昆蟲,但也可分泌類似作用的警告物質,同時也證明此物質存在於軟便與唾液中,其中以軟便的驅散效果較強,且不同性別間皆具有驅離作用,跨物種間(對蟋蟀)也有作用。若去除反應者的觸角後,警告物質的驅離效果降低,並延長了反應潛伏期,證明觸角是此警告物質的接受器官。我們也利用沾附酒精的濾紙吸附蟑螂所產生的警告物質,也有相同的驅散效果。利用後腿基節屈肌的肌肉電位圖(electromyography, EMG)記錄蟲體對此物質的反應電位,亦顯示受到警告物質的影響,可使步足肌肉放電頻率增加。

Social child labor?-Preliminary study of non-cocooning silk from larvae of Gray-Black Spiny ant, Polyrhachis dives(Hymenoptera Formicidae)

大部分會吐絲的昆蟲都是幼蟲時期為了結繭化蛹而從絲腺分泌絲,僅少數昆蟲利用幼蟲吐絲作為巢材,例如織工蟻。並非所有的螞蟻幼蟲都會吐絲,而像黑棘蟻工蟻調控幼蟲吐絲形成巢室內壁則非常罕見。本研究即探討黑棘蟻工蟻對非結繭蟻絲之行為調控,並分析蟻絲成份,比較蟻絲與其他有絲昆蟲的異同。結果顯示,無論從物理、化學或生理學的證據來說,黑棘蟻非結繭蟻絲都呈現特殊的適合性,用以維護蟻巢內環境的穩定。本研究為首次發表黑棘蟻幼蟲非結繭蟻絲的游離胺基酸之報告,富含丙胺酸和甘胺酸的蟻絲蛋白,是否繼蠶蜂之後可為人類所用,則有待更進一步的研究。

同類相食行為的新發現

同類相食行為廣泛發生於動物界,兩種可能原因:個體的特殊營養需求和族群的汰弱留強策略。觀察雜食性的高音符絲鱉甲蝸牛(Macrochlamys hippocastaneum),初步發現同類相食行為與蝸殼破裂與否有關,殼完整的個體間不會發生相食行為(100%),且當破殼程度愈大愈易發生。食性實驗中攝取過植物性養分的個體傾向選擇同類相食(χ2=22.04,***P<0.001),同時提供同、異類蝸牛內臟時則未顯著選擇同類(χ2=3.76, P=0.053),因此未能充分支持特殊營養需求。然而,此種蝸牛會追蹤破殼同類分泌之特殊黏液且具顯著趨向性(χ2=13.06, ***P<0.001),與距離呈負相關(χ2=6.53, *P<0.05)。觀察腹足顯微構造中,發現內有特殊的疏鬆組織與大量分泌細胞,且通往尾端分泌特殊黏液的開口部位。結果證實破殼受傷個體產生的特殊黏液會主動引起同類相食,支持汰弱留強的族群策略,且物質誘發同類相食模式為動物行為研究中首次發現。