The Bandy-Dandy

Order: Eucinetophiformes

Family: Eucinetophidae

Genus: Eucinetophis

Evolutionary history, marked out by hundreds of millions of years of evolution, is a complex timeline, in which clades diversify and multiply, branching off at different periods of time. Compare it to a tree, where the branches split off and diversify on their own.

So, if that is the case, what is the first branch of the pelagys evolutionary tree?

In the shallows, we may find our answer, in an unusual, tiny pelagys just 7 centimetres long, the bandy-dandy. It is a relict from the past, one of the forty species of the small clade, eucinetophiformes (it is the namesake and type species of the group), primitive pelagys which branched off from the rest of the pelagys 180 million years ago. 

While certainly not the first radiation in the group, it is the earliest which still survives to this day, and gives us a rough idea on how the ancestral pelagys might've looked like. The cephalon is thick, stocky and bulbous, and the gills possess fragile skin and pump out water actively, somewhat like a siphon. On the contrary, the limb girdle is thing, appearing as if the body was cinched in between the ophistoma and cephalon. By far the longest portion of the body is the long ophistoma, with the caudal rhachis running (nearly) the entire length. This creates a bauplan analogous to an eel, and they appear to fill a similar niche. The bandy-dandy, named because of its banded patterns, swims in schools upwards, with their vertical slitted eyes, like a cat, which, at a vertical position, will function similar to horizontal eyes of the most pelagys and grant the bandy-dandy a wide field of view. Swimming vertically in a group, they look for plankton and small nekton in the water column to consume. 

Bandy-dandies rarely swim away from their shoals, as trusting the protection in numbers, simply swim in formation. As a shoal, they keep on lookout for predators, and will scatter upon seeing a disturbance. Despite being regularly skittish, they are quite aggressive, attempting to bite and nip smaller pelagys and jetgillers, and often irritate herbivores by burrowing into their gills to bite and attempt to ward them away. When swimming vertically, they employ a method of swimming called amiiform swimming, undulating the rhachis slowly, creating thrust. It is a slow method of locomotion, yet is efficient for moving at certain positions and holding themselves in the water column, and is easily transferred to faster, tail-propelled locomotion. Agile, they easily evade predators and their excellent vision can find food quickly in the water column, all their ingredients to amazing success among the carpgrass. A unique feature of the bandy-dandy, however, is their reproductive system. 

The eucinetophiformes retains ancestral traits of the pelagys, such as a lack of a reproductive appendage at the end of the tail. The bulbous portion of the pelagys tail is the reproductive appendage, and protects and holds reproductive organs. The bandy-dandy and its relatives lacks this appendage, and relies on a modified portion of the tail to store organs such as the testis and ovaries, but the penis is exposed to the water. To avoid injury, the bandy-dandy will retract a portion of it into the tail, and then hold the rest of the penis exposed. During reproduction, the strand of eggs pelagys are known for is detached, as in fashion of other pelagys, however, have a spinous appendage at the end of this stringy strand of tissue. While the egg strand drifts through the water, it hooks onto any passing pelagys, and acts as a solid foundation, promoting its safety. 

This strategy of reproduction is convergently evolved among various pelagys lineage, however it was first monopolised by the eucinetophiforms. The success of this early radiation of pelagys is one that spanned over a hundred million years, and are one of the longest success stories on the planet of Alladoras.