磷沙蠶科

磷沙蠶科
科學分類
界：	動物界 Animalia
門：	環節動物門 Annelida
綱：	多毛綱 Polychaeta
亞綱：	隱居亞綱 Sedentaria
科：	磷沙蠶科 Chaetopteridae

磷沙蠶科（學名：Chaetopteridae）是多毛綱隱居亞綱之下的一個海洋濾食蠕蟲科，終生管棲，居住在海底沉積物或硬基層內挖掘的垂直或U形棲管內。蟲體本身亦已高度適應於在牠們分泌的棲管內生活：棲管的兩端開口露出泥沙表面，而其身體分為三段，負責身體的不同功能（異律分節）。這三段為：

• 前段：背腹扁平，有9對圓錐形突起,圍口節為一寬領狀,背面有1對圍口觸手,口前葉退化；
• 中段由5節組成,第一節兩側有1對大的翼狀突起；
• 後段約有30多個體節組成。

另外，疣足的腹鬚轉變為吸盤，用以附著在管壁上；而其背鬚則轉變成肌肉質的鼓動器，能鼓動水流，以獲得食料和氧氣。

Inside the tube the animal is segmented and regionally specialized, with highly modified appendages on different segments for cutting the tunnel, feeding, or creating suction for the flow of water through the tube home. The modified segments for feeding are on the 12th segment from the head for members of this family.

該管是分段和區域專業的，具有高度修改的附件用於切割隧道，給水或通過管道產生水流。 飼養改良的部分在這個家族的成員頭上的第12段。

若蟲

本科物種的若蟲在所有多毛綱的物種來說體型最大，從 0.4 mm 到 2.5 mm不等；有紀錄最大的長達 12 mm; the late stage of an unknown phyllodicid species). Chaetopteridae larvae are barrel-like in form with one to two ciliated bands at the midsection. They also have a large buccal funnel. These larvae are often long lived and effectively disseminate, although are constrained geographically to their appropriate ranges for successful adult growth. The most common form of larval developmental plan for polychaetes is the trochophore larvae. The trochophore will add segments sequentially from a posterior growth zone to produce a nectochaete larva. Chaetopterus represents a distinct deviation from this general design. At no point in larval growth stages does the metatrochophore take on the clearly segmented form of the typical nectochaete larva. The 15 segments of Chaetopterus are formed by subdivision of existing anlage.

Feeding

The Chaetopteridae have several genera with peculiar and well-studied filter feeding mechanisms. The genera Chaetopterus, Mesochaetopterus, and Spiochaetopterus feed using a thin mucus net suspended across the upper portion of their tube. The mucus net is secreted by a hooplike structure called the aliform notopodia arch. The net can grow at a rate as great as one millimeter per second as water currents generated by the notopodial fans pass plankton through the net. When the net grows large enough it contacts the ciliated cup, which rolls up the net. When the roll becomes large the net is disconnected from the aliform notopodia and is rolled into a ball before the ciliated mid-dorsal groove transports it to the mouth.

分類

本科物種包括下列三個屬：

• 磷沙蠶屬 Chaetopterus
• Phyllochaetopterus屬
• Spiochaetopterus屬

另外，分子生物學研究表明，本分類單元是環節動物的基底，位處星蟲動物門之下。

外部連結

• Some relevant images of adult Chaetopteridae （頁面存檔備份，存於網際網路檔案館）