Black-Knobbed Map Turtle

graptemys nigrinoda

The Black-Knobbed Map Turtle is a striking and highly specialized aquatic turtle endemic to the Mobile Bay drainage system in Alabama and Mississippi. Named for the prominent, dark, bulbous spines protruding from its vertebral scutes, this medium-sized turtle is a favorite among herpetologists and wildlife observers. It spends a massive portion of its day basking on fallen logs and branches hanging over fast-flowing rivers. This species is highly adapted to riverine environments, displaying exceptional swimming capabilities and a specialized diet that helps keep river ecosystems balanced. Due to its limited geographic range and sensitivity to water pollution, it serves as an important indicator species for the health of freshwater systems in the southeastern United States.

生息地: Found in moderate to fast-flowing river systems, particularly those with clay or sandy bottoms and abundant basking sites like fallen trees and brush piles.

外見

This turtle is easily recognized by the 2 to 4 black, knob-like projections on the center of its carapace, which resemble a miniature mountain range. The carapace itself is olive-brown to dark green, featuring fine, yellow-to-orange circular markings on each scute that resemble a map. The plastron is yellow with a bold, dark pattern along the seams. Its head, neck, and limbs are dark grey or black, decorated with vibrant yellow stripes, including a distinctive yellow crescent behind each eye. Females are significantly larger than males, reaching up to 22 cm in carapace length, while males rarely exceed 12 cm.

界Animalia門Chordata綱Reptilia目Testudines科Emydidae属Graptemys

Black-Knobbed Map Turtle

カテゴリ

爬虫類

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

The prominent black spikes on their shells tend to wear down and become more rounded or flattened as the turtle ages.

The species exhibits temperature-dependent sex determination, meaning the temperature of the nest decides whether the hatchlings are male or female.

They are incredibly shy baskers; they will dive into the river at the slightest shadow, sound, or movement from hundreds of feet away.

特殊能力

Its streamlined shell and protruding vertebral knobs help break water tension, allowing the turtle to navigate fast-flowing river currents with ease.

They possess an acute ability to regulate body temperature by balancing extensive basking sessions on elevated logs with quick plunge-dives into cool river waters.

Adult females develop broad, flat alveolar surfaces on their jaws, which allow them to effortlessly crush hard-shelled mollusks and snails.

サイズと詳細

長さ: 7-22 cm
体重: 0.1-1.2 kg
寿命: 15-30 年
Top Speed: 12 km/h
一度の産卵数: 1-7
抱卵期間: 50-70 日

食性と食事

This species primarily feeds on freshwater sponges, bryozoans, aquatic insects, and small mollusks. Females, with their larger jaws, consume more hard-shelled prey than males.

年齢による違い: Juveniles and adult males feed heavily on soft-bodied aquatic insects, while mature females shift their diet toward larger, hard-shelled mollusks and snails due to their increased jaw size.

主な食物

Freshwater sponges
Bryozoans
Aquatic insects
Snails
Clams

採餌方法

Foraging

生態系とのつながり

hunts

Asian Clam

Corbicula fluminea

Preys upon freshwater bivalves and snails in river beds.

eaten by

Raccoon

Procyon lotor

Eggs and hatchlings are heavily preyed upon along the sandy riverbanks.

hunts

Magnificent Bryozoan

Pectinatella magnifica

Feeds extensively on bryozoan colonies growing on submerged wood.

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

Black-Knobbed Map Turtleを見分けるには？

Black-Knobbed Map Turtle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。

Black-Knobbed Map Turtleの長さは何ですか？

7-22 cm

Black-Knobbed Map Turtleの体重は何ですか？

0.1-1.2 kg

Black-Knobbed Map Turtleの寿命は何ですか？

15-30 年

Black-Knobbed Map Turtleのtop Speedは何ですか？

12 km/h

Black-Knobbed Map Turtleは何を食べますか？

This species primarily feeds on freshwater sponges, bryozoans, aquatic insects, and small mollusks. Females, with their larger jaws, consume more hard-shelled prey than males.

Black-Knobbed Map Turtleは通常どこに生息していますか？

Found in moderate to fast-flowing river systems, particularly those with clay or sandy bottoms and abundant basking sites like fallen trees and brush piles.

Black-Knobbed Map Turtleはどのように狩りをしますか？

Foraging