Which of the following is a limitation of models

Jellyfish have been around for more than 650 million years, which means that they outdate both dinosaurs and sharks.
An Electric Eel is known to produce electricity sufficient enough to light up to 10 electric bulbs.
Dolphins sleep with only half of their brain and with one eye open so they can watch for predators and other threats.
An Octopus has three hearts and the color of its blood is blue.
At 188 decibels, the calls of blue whales is the loudest sound made by any animal on the planet.
Seahorses are the only animals in which the male, not the female, gives birth and care for their young.
A shrimp's heart is in their head.
Sea sponges have no head, mouth, eyes, feelers, bones, heart, lungs, or brain, yet they are alive.
Turtles live on every continent except Antarctica.