In a unique family of fishes, only two species exist. Consider that the family that contains tuna, mackerel, and bonitas contains 51 species. The longer Gigantura indica and the shorter, robust Gigantura chun, are the only known species for the family Giganturidae. The family is rather aptly named the telescope fishes because of the forward-pointing, ‘‘telescopic’’ eyes with large lenses. These eyes can be near 4% of the body length.
While the fishes are known from net captures, prior the only known video was this video by the Monterey Bay Aquarium Research Institute (MBARI) published on back in 2016 capturing two individuals at 1200m.
Both fish face upward orienting those big tubular eyes toward the surface. Those eyes and orientation are thought to be an adaptation to seeing prey above silhouetted against the light coming down from the surface.
A recently published paper by Kupchik, Benfield, and Sutton provides two more videos from 2015 taken in the Gulf of Mexico of these unique fish. This video was taken from a remotely operated vehicle at near 900m. In one of the videos, like the video from above, there is a pairing of fish.
This pairing may reflect that telescope fishes are likely simultaneous hermaphrodites, meaning they possess both male and female sexual organs at the same time. In this case, the pairing as an adaption would allow both individuals to exchange genes. These new videos of this amazing fish demonstrate unique adaptations for feeding, surviving, and reproducing. In the extremes of the deep-sea novel adaption is a necessity.
All this is leaving me asking what’s up with all these sightings?
Kupchik, Matthew J., Mark C. Benfield, and Tracey T. Sutton. “The First In Situ Encounter of Gigantura chuni (Giganturidae: Giganturoidei: Aulopiformes: Cyclosquamata: Teleostei), with a Preliminary Investigation of Pair-Bonding.” Copeia 106.4 (2018): 641-645.
from Deep Sea News https://ift.tt/2UyaGaD https://ift.tt/2ruq0HR
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