Happy World Octopus Day! The giant Pacific octopus explores its world using touch and smell, thanks to the thousands of chemical receptors and millions of texture receptors that line the rims of its suckers.
Studies have shown that octopuses learn easily, including learning by observation of another octopus.
They can solve problems, as when they remove a plug or unscrew a lid to get prey from a container.
They are the first invertebrates to be seen using tools,
such as using coconut shells to hide from potential predators and using
rocks and jets of water in a way that could be classified as tool use.
Common octopuses will collect crustacean shells and other objects to
construct fortresses, or “gardens,” around their lairs. Other octopuses
carry shells for protection.
They have been found to play with a ‘toy’ and to have individual
responses and individual temperaments, with some scientists believing
they have individual personalities.
All octopuses are venomous, but only the small blue-ringed octopuses are known to be deadly to humans.
(via Starfish and Sand Dollar Knobs)
Observe the disc shaped objects sticking out of the sand as the octopus swims merrily along. Those are living Sand Dollars!
But a creepy chorus. Australian scientists have found evidence that certain species of fish actually sing together, in a chorus, each day at dawn and dusk. The results are published in the Journal Bioacoustic.
Researchers recorded vocalization of fish
over an 18-month period
in the coastal waters off Port Headland in Western Australia, and what they found were seven distinct fish choruses, happening at dawn and at dusk
Sound plays an important role in various behavioural functions and life stages of fish, such as spawning, feeding, territorial disputes or distress. Noctural fishes use calls to stay together when they hunt, while fish that are active during the day use sound to defend their territory.
Cataloguing the acoustic characteristics and temporal patterns of choruses and their locations is important, can provide significant information for long-term monitoring of vocal fishes and their ecosystems. A silent aquatic environment means ecosystemic problems such as lower species abundance and absence of fish.
Photo:
mulloway (Argyrosomus japonicus) by Rudie Kuiter
