Topic
Pearleye
About: Pearleye is a research topic. Over the lifetime, 3 publications have been published within this topic receiving 5 citations. The topic is also known as: Scopelarchidae.
Papers
TL;DR: Paleoecological considerations suggest that Benthalbella praecessor was a deep-sea fish that inhabited the cold-temperate waters of the northwestern Pacific about 14 Ma, and appears to be closely related to the extant B. dentata.
Abstract: Fishes of the family Scopelarchidae, commonly known as pearleyes, are basal alepisauroids that occur worldwide at depths between 300 and 1,000 m. A new pearleye species, Benthalbella praecessor, sp. nov., is described from the middle Miocene (late Langhian–early Serravallian; 14.6–13.1 Ma) deposits of the Kurasi Formation, Sakhalin Island, Russia, based on 24 well-preserved specimens. These specimens consist primarily of articulated skeletons and represent the first fossil skeletal remains for the family Scopelarchidae. Benthalbella praecessor appears to be closely related to the extant B. dentata and is characterized by a unique combination of morphological and meristic features, including 54–56 vertebrae, dorsal fin with 8–9 rays, anal fin with about 19–22 rays, very short pectoral fin containing 26–28 rays, elongate pelvic fin, enlarged second infraorbital, subopercle larger than the opercle, and urohyal with a posterodorsally directed hook-like process along its anterodorsal margin. Paleoecological considerations suggest that Benthalbella praecessor was a deep-sea fish that inhabited the cold-temperate waters of the northwestern Pacific about 14 Ma.
4 citations
TL;DR: The fossils of the new Oligocene species described herein represent the oldest known skeletal record of Scopelarchidae and both morphological and meristic features suggest a certain degree of similarity between S. neamticus sp.
Abstract: A new pearleye species of the alepisauroid family Scopelarchidae, Scopelarchoides neamticus sp. nov., is described herein based on two specimens from the Oligocene Lower Dysodilic Shales Formation, cropping out in the Pietricica Mountain, Romanian Eastern Carpathians. The new species described herein exhibits a unique combination of features (including head length about 25% of SL; coracoid remarkably expanded; both preorbital and postorbital lengths larger than orbit diameter; 50 or 51 vertebrae; dorsal fin with nine or ten rays; anal-fin with 28 rays; length of anal fin base about 30% of SL; preanal distance almost 60% of SL; pelvic fin insertion located just under the second dorsal fin ray; pectoral fins only slightly longer than pelvic fins; caudal fin with 19 principal rays plus 14 upper and 13 lower procurrent rays) that justifies its recognition as a new species of the genus Scopelarchoides. Both morphological and meristic features suggest a certain degree of similarity between S. neamticus sp. nov. and the extant species Scopelarchoides signifer. The fossils of the new Oligocene species described herein represent the oldest known skeletal record of Scopelarchidae.
1 citations
TL;DR: In this paper, a comparative transcriptomic approach was used to study 20 deep-sea fishes from eight teleost orders to show that adults mostly rely on rod opsin (RH1) for vision in dim light, larvae almost exclusively express midwavelength-sensitive cone opsins (RH2) in their retinas.
Abstract: The ontogeny of the vertebrate retina is thought to follow a conserved pattern whereby cone photoreceptors develop first and rod photoreceptors are added only at later developmental stages. Whether this is also the case for species that use only rods as adults, such as many deepsea fishes, remained unclear. Since many deep-sea fishes start their lives in the shallow, well-lit epipelagic zone cones might still be favoured during early developmental stages. Using a comparative transcriptomic approach in 20 deep-sea species from eight teleost orders, we show that while adults mostly rely on rod opsin (RH1) for vision in dim light, larvae almost exclusively express mid-wavelength-sensitive cone opsins (RH2) in their retinas. The phototransduction cascade genes follow a similar ontogenetic pattern of cone-followed by rodspecific gene expression in most orders, except for the pearleye and sabretooth (Aulopiformes), in which the cone cascade remains dominant throughout development. Hence, our findings provide strong molecular support for a conserved cone-to-rod retinal development in vertebrates.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2019 | 1 |
| 2018 | 1 |