The sunlight arrowhead has doubled in size compared to its ancestor, the arrowhead, thanks in part to a diet rich in a wide variety of planktonic species. With little direct competition in its niche, it has managed spread along the coasts of Barlowe and Dixon, and they now thrive in the temperate to tropical waters. There presence alongside other species of arrowheads has begun to put pressure on several species of distantly related rorms. While the latter have long since been established in the waters of Sagan IV, the evolutionary adaptations of the Arrowheads, such as their improved feeding structure and tiny stinging cells for incapacitating larger prey, have given them a definitive edge over them.
The exoskeletons of the sunlight arrowheads have evolved a smoother carapace in order to make them more hydrodynamic. In addition, their tails are now completely encased in the aragonite-infused chitinous shell, allowing them to deliver more thrust with each flick. Finally, the mandible-like tusks have further extended, and can even be brought together with the top of the "mouth" in order to create a tight seal in order to prevent prey from escaping the tentacled maw within.
Beyond these morphological changes, the sunlight arrowheads are similar to the arrowheads in regards to their diets and reproductive strategies.