Astrapes

MORPHOLOGICAL FEATURES

• Size: Reaches up to 38 cm (15 inches) in total length.

• Body Shape: Flattened, disc-like body typical of rays, with pectoral fins extending to form the disc. The body is broad and rounded.

• Eyes: Rudimentary and covered by skin, making the species functionally blind.

• Electric Organs: Located on either side of the head, specialized organs generate electric discharges used for prey capture and defense.

• Fins:

• Pectoral Fins: Large and rounded, forming a disc around the body.

• Dorsal Fins: Two small dorsal fins located near the base of the tail.

• Pelvic Fins: Small, contributing to stabilization.

• Caudal Fin: Relatively small and short tail.

• Coloration: Dark brown or grey on the dorsal side for camouflage in deep waters, with a lighter ventral surface.

UNIQUE FEATURES

• Blindness: Unlike most rays, Typhlonarke aysoni is functionally blind, as its eyes are rudimentary and covered by skin, an adaptation to its deep-sea habitat where vision is not a primary sense.

• Electric Discharge: The ray has highly specialized electric organs capable of producing low-voltage shocks to stun prey or deter predators. This is a unique feature that helps compensate for its lack of vision.

• Deep-Sea Adaptation: The species has adapted to life in deep waters with low light and high pressure, featuring slow movement, benthic lifestyle, and a reliance on electroreception to detect prey.

HABITAT AND DISTRIBUTION

• Geographic Range: Endemic to waters around New Zealand.

• Depth Range: Found in deep-sea habitats at depths of 300 to 600 meters.

• Habitat: Inhabits the seafloor (benthic zone) of continental slopes and deep coastal waters, typically over soft, muddy substrates.

ECOLOGY

DIET:

• Primarily preys on small benthic invertebrates and fish.

• Uses electric discharges to incapacitate prey before feeding.

• Predators: Potential predators include larger deep-sea fish and sharks, though its electric discharge acts as a defense mechanism.

BEHAVIOR:

• A slow-moving, benthic dweller that spends much of its time resting on the seafloor.

• Tends to bury itself partially in sediment to remain hidden while waiting to ambush prey.

REPRODUCTION AND LIFE CYCLE

• Reproduction Mode: Ovoviviparous – eggs develop and hatch inside the female, and live young are born.

• Gestation: The gestation period is not well documented but follows the general pattern of live-bearing rays, with developing embryos nourished within the female.

• Litter Size: Typically small, with only a few offspring produced per reproductive cycle.

• Offspring Development:

• Young are born fully developed and independent, capable of producing electric discharges from birth.

• Juveniles remain benthic and have similar feeding behaviors to adults.