Fish are the most diverse group of vertebrates in the world, exhibiting an enormous variety of morphology, ecology, behavior; etc. This blog will explore the diversity of the 28,000 recorded species of fishes while discussing the biology that makes this group of organisms so amazing.
(Photo from Gibb A.C. et al 2011)
The top fish labeled “Gambusia” is the mosquito fish (Gambusia affinis), a fish that lives in little ponds that dry up frequently. As a consequence of their habitat, they voluntarily strand themselves out of the water in order to find new bodies of water.
The bottom fish labeled “Danio” is the zebrafish (Danio rerio), a fish that lives in relatively stable bodies of water, and is not known to voluntarily emerge itself out of water.
Alice Gibb from Northern Arizona University did a study on these fish and found that mosquito fish are more efficiently able to move across land than the zebrafish despite their morphological and anatomical similarities. Not only does the mosquito fish jump at a near optimal ~46 degree take-off angle to the ground (compared to the ~76 degree take-off angle of zebrafish), they are able to maintain their head oriented in the direction of travel, presumably to maintain vision of their targeted destination (such as the nearest body of water). Zebrafish on the otherhand flip over and are therefore, thought to not be able to maintain vision on a specific target, suggesting that they are just frantically trying to get back in water with no strategy.
This study suggests that there is no necessity for novel morphological traits to develop in order for fish to move effectively on land.
Videos of fish jumping here.
A cool gif of another species of fish, the mangrove rivulus (Kryptolebias marmoratus), jumping here.
Source: Gibb A.C. et al 2011