abactinally
adv. placeadv. in a direction away from the mouth of a sea creature like a starfish. You use this when talking about the top side of animals that have bodies shaped like a circle.
adv. situated or occurring in a direction away from the oral surface of a radially symmetrical animal. Used primarily in zoological descriptions of echinoderms and cnidarians.
The biologist examined the starfish abactinally to see its top surface.
The researcher noted that the spines were distributed abactinally across the upper surface of the sea urchin.
While the oral side of the organism is specialized for feeding, the structures located abactinally serve primarily for protection and waste expulsion in many radial species.
Typically used in technical biological descriptions to indicate anatomical direction relative to the mouth.