Signal Crayfish

pacifastacus leniusculus

The Signal Crayfish is a robust, fascinating freshwater crustacean native to western North America. While cherished in its homeland, it has gained notoriety across Europe and Asia as a highly successful invasive species. Extremely adaptable and aggressive, this crayfish can tolerate a wide range of water conditions and is famous for outcompeting local species wherever it is introduced. Its common name comes from the bright white or turquoise patches at the hinge of its claws, resembling a railway signalman's flags. This hardy creature plays a major role in aquatic ecosystems, modifying riverbeds through its extensive burrowing habits and acting as a key player in freshwater food webs. Spotting one of these mini-lobsters crawling along a riverbed offers an exciting glimpse into the hidden, active world of freshwater invertebrates.

生息地: Typically found in clear, cool freshwater environments such as streams, rivers, lakes, and ponds, where it utilizes rocky substrates or clay banks to dig protective burrows.

外見

A relatively large freshwater crayfish, the Signal Crayfish typically measures between 9 to 16 centimeters in length. Its body is smooth, lacking the heavy spines found on some other crayfish species, and varies in color from bluish-brown to reddish-brown. Its most defining field identifier is the bright white or light-blue patch located on the hinge of its massive, robust claws. The undersides of its claws are a striking, bright red, which it flashes aggressively when threatened. It possesses a smooth carapace, long antennae, and a fan-shaped tail used for rapid backward swimming.

界Animalia門Arthropoda綱Malacostraca目Decapoda科Astacidae属Pacifastacus

Signal Crayfish

カテゴリ

Animal

レア度

Common

危険度

1/5 · 非常に低い

スナップ

最初にスナップしよう！

おもしろい事実

Female signal crayfish carry their fertilized eggs under their tails for up to eight months, protecting them through the cold winter.

The distinctive white patches on their claws mimic the signaling flags once used by railway workers, giving them their 'signal' name.

Their intensive burrowing behavior can undermine riverbanks, occasionally causing severe bank erosion and collapse in areas with high populations.

特殊能力

Carries the lethal water mold known as crayfish plague without suffering significant illness, acting as a highly effective vector that devastates native competitors.

Capable of crawling substantial distances over damp land at night to move between disconnected water bodies or escape poor water conditions.

Can voluntarily shed a claw or leg to escape a predator's grasp and fully regenerate the lost limb during subsequent molting cycles.

サイズと詳細

長さ: 9+ cm
体重: 0.05+ kg
寿命: 10+ 年
一度の産卵数: 100200+
抱卵期間: 150+ 日

食性と食事

An opportunistic feeder that consumes almost any organic matter it can find, balancing its diet between vegetation and animal protein.

年齢による違い: Juveniles feed heavily on protein-rich aquatic invertebrates, while mature adults consume a higher ratio of plant matter and decaying leaf litter.

主な食物

Aquatic plants
Insects and larvae
Snails
Small fish
Detritus

採餌方法

Foraging

生態系とのつながり

competitor

Noble Crayfish

Astacus astacus

Outcompetes this native European species for food and shelter while transmitting lethal crayfish plague.

eaten by

Eurasian Otter

Lutra lutra

Preys heavily upon signal crayfish, utilizing them as a valuable, protein-rich aquatic food source.

parasite

Crayfish Plague

Aphanomyces astaci

Acts as a carrier for this deadly parasitic water mold, spreading it to vulnerable native crayfish species.

特徴

このオブジェクトにはまだ特徴バッジが割り当てられていません。

別名

まだ別名はありません。

コレクション

テーマが追加されると、このオブジェクトのコレクションがここに表示されます。

安全性

危険度

1/5 · 非常に低い

まだ特別な安全上の注意はありません。

よくある質問

Signal Crayfishを見分けるには？

Signal Crayfishを識別する最も簡単な方法は、Snappit自然識別アプリを使用することです。

Signal Crayfishの長さは何ですか？

9+ cm

Signal Crayfishの体重は何ですか？

0.05+ kg

Signal Crayfishの寿命は何ですか？

10+ 年

Signal Crayfishは何を食べますか？

An opportunistic feeder that consumes almost any organic matter it can find, balancing its diet between vegetation and animal protein.

Signal Crayfishは通常どこに生息していますか？

Typically found in clear, cool freshwater environments such as streams, rivers, lakes, and ponds, where it utilizes rocky substrates or clay banks to dig protective burrows.

Signal Crayfishはどのように狩りをしますか？

Foraging

Signal Crayfishの一度の産卵数は何ですか？

100200+