Okamejei panayensis

Okamejei panayensis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Order:	Rajiformes
Family:	Rajidae
Genus:	Okamejei
Species:	O. panayensis
Binomial name
	Okamejei panayensis; Misawa, Babaran & Motomura 2022

Okamejei panayensis is a demersal fish belonging to the skate family, occurring in nearshore temperate environments and deep-water tropical and boreal regions.^[1]

Habitat

Okamejei panayensis has been found in the waters off the South China Sea near Iloila, Philippines, close to the Philippine Rise.^[2] This area is on a continental ridge, with muddy sediment, inland bays and wide tidal flats where other Rajidae species are known to reside and spawn.^[3]

Physical description

Like all skates, O. panayensis has a depressiform, cartilaginous, rhombic body that allows it to move closely along the seafloor.^[4] It has a mouth on the ventral side and a set of spiracles behind its eyes. It has ventral sensory pores (similar to ampullae in other forms of Chondrichthyes), with a lack of pores on the central abdominal region and pelvic lobes.^[2]

The ventral surface of the disk is broadly white, with a pale brown margin, and it is darkly pigmented at the bases of the pectoral fins and the nasal curtain. One distinguishable characteristic of the species is its densely scattered black spots on the dorsal disc, that do not come together to form patches. This feature alongside a yellowish-brown dorsal surface helps to visually differentiate it from O. hollandi and O. mengae, which are otherwise similar in appearance.^[4]

Okamejei panayensis has the least amount of pectoral fin radials of any organism in its genus, tallying in at 75 to 76 radials, and the second smallest preorbital snout length, which measures 14.3% of the total body length.^[2]

Diet

Pelagic food sources such as squid, krill, shrimp, crustaceans, shelled mollusks, and other benthic invertebrates are typically eaten by demersal elasmobranchs like O. panayensis, indicating that this species likely has an equivalent diet.^[5]

Conservation status

The size of the O. panayensis population is unknown. However, most Rajidae species are susceptible to overfishing due to their low reproductive rate and a direct relationship between stock size and recruitment.^[6]

References

Citations

^ Ebert & Bizzarro 2007.
^ ^a ^b ^c Misawa, Babaran & Motomura 2022.
^ Youn et al. 2022.
^ ^a ^b Ng et al. 2023.
^ Ebert & Sulikowski 2008.
^ Joung et al. 2011.

Sources

Misawa, Ryo; Babaran, Ricardo P.; Motomura, Hiroyuki (May 19, 2022). "Okamejei panayensis sp. nov., a new skate (Rajiformes: Rajidae) from the Philippines". Ichthyological Research. 70 (1). Springer Science and Business Media LLC: 161–176. doi:10.1007/s10228-022-00874-1. ISSN 1341-8998. S2CID 248939185.
Ng, Shing-Lai; Ho, Hsuan-Ching; Joung, Shoou-Jeng; Liu, Kwang-Ming (May 4, 2023). "Okamejei picta sp. nov., a new rajid skate from the South China Sea (Rajiformes: Rajidae)". Zootaxa. 5278 (1). Magnolia Press: 103–118. doi:10.11646/zootaxa.5278.1.4. ISSN 1175-5334. PMID 37518295. S2CID 258503664.
Okamejei ornata: Ebert, D.A., Khan, M., Ali, M. & Akhilesh, K.V., IUCN, February 9, 2017, doi:10.2305/iucn.uk.2017-2.rlts.t107604828a109922504.en
Youn, Byoung-Il; Choi, Dong-Hyuk; Lee, Seung-Hwan; Han, Kyeong-Ho; Lee, Seung-Jong; Kwon, Dae-Hyeon; Kim, Maeng-Jin (August 3, 2022). "Spawning Period and Size at Maturity of the Ocellate Spot Skate Okamejei kenojei in the West Sea of Korea". Journal of Marine Science and Engineering. 10 (8). MDPI AG: 1067. doi:10.3390/jmse10081067. ISSN 2077-1312.
Ebert, David A.; Bizzarro, Joseph J. (February 14, 2007). "Standardized diet compositions and trophic levels of skates (Chondrichthyes: Rajiformes: Rajoidei)". Environmental Biology of Fishes. 80 (2–3). Springer Science and Business Media LLC: 221–237. Bibcode:2007EnvBF..80..221E. doi:10.1007/s10641-007-9227-4. ISSN 0378-1909. S2CID 1382600.
Chiquillo, Kelcie L.; Ebert, David A.; Slager, Christina J.; Crow, Karen D. (2014). "The secret of the mermaid's purse: Phylogenetic affinities within the Rajidae and the evolution of a novel reproductive strategy in skates". Molecular Phylogenetics and Evolution. 75. Elsevier BV: 245–251. Bibcode:2014MolPE..75..245C. doi:10.1016/j.ympev.2014.01.012. ISSN 1055-7903. PMC 4036632. PMID 24486989.
Packer, David B.; Zetlin, Christine A.; Vitaliano, Joseph J. (2003). "Essential fish habitat source document. Clearnose skate, Raja eglanteria, life history and habitat characteristics". Welcome to the NOAA Institutional Repository. Retrieved November 28, 2023.
Joung, Shoou-Jeng; Lee, Pei-Hsuan; Liu, Kwang-Ming; Liao, Yih-Yia (2011). "Estimates of life history parameters of the sharpspine skate, Okamejei acutispina, in the northeastern waters of Taiwan". Fisheries Research. 108 (2–3). Elsevier BV: 258–267. Bibcode:2011FishR.108..258J. doi:10.1016/j.fishres.2010.12.013. ISSN 0165-7836.
Luer, Carl A.; Gilbert, Perry W. (1985). "Mating behavior, egg deposition, incubation period, and hatching in the clearnose skate, Raja eglanteria". Environmental Biology of Fishes. 13 (3). Springer Science and Business Media LLC: 161–171. Bibcode:1985EnvBF..13..161L. doi:10.1007/bf00000926. ISSN 0378-1909. S2CID 23070359.
Carrier, Jeffrey C.; Musick, John A.; Heithaus, Michael R. (March 9, 2010). Sharks and Their Relatives II. Boca Raton (Fla.): CRC Press. ISBN 978-1-4200-8047-6.
Ebert, David A.; Sulikowski, James (December 25, 2008). Biology of Skates. Dordrecht: Springer Science & Business Media. ISBN 978-1-4020-9703-4.
Treloar, Michelle A.; Laurenson, Laurie J. B.; Stevens, John D. (March 24, 2007). "Dietary comparisons of six skate species (Rajidae) in south-eastern Australian waters". Environmental Biology of Fishes. 80 (2–3). Springer Science and Business Media LLC: 181–196. Bibcode:2007EnvBF..80..181T. doi:10.1007/s10641-007-9233-6. ISSN 0378-1909. S2CID 12137056.
Lucifora, L. O.; García, V. B. (May 11, 2004). "Gastropod predation on egg cases of skates (Chondrichthyes, Rajidae) in the southwestern Atlantic: quantification and life history implications". Marine Biology. 145 (5). Springer Science and Business Media LLC: 917–922. Bibcode:2004MarBi.145..917L. doi:10.1007/s00227-004-1377-8. ISSN 0025-3162. S2CID 53508039.
Swain, Douglas P.; Benoît, Hugues P.; Hammill, Mike O.; Sulikowski, James A. (June 12, 2019). "Risk of extinction of a unique skate population due to predation by a recovering marine mammal". Ecological Applications. 29 (6). Wiley: e01921. Bibcode:2019EcoAp..29E1921S. doi:10.1002/eap.1921. ISSN 1051-0761. PMID 31059188. S2CID 145820434.