Photoblepharon steinitzi

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Photoblepharon steinitzi
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Trachichthyiformes
Family: Anomalopidae
Genus: Photoblepharon
Species:
P. steinitzi
Binomial name
Photoblepharon steinitzi
T. Abe & Haneda, 1973
Synonyms

Photoblepharon palpebratus steinitziAbe & Haneda, 1973

Contents

The flashlight fish (Photoblepharon steinitzi) is a species of anomalopid fish of the order Beryciformes. It is native to the western Indian Ocean and the Red Sea where it is found near coral reefs. It is a nocturnal predator, hiding in crevices and caves by day and emerging to feed at night. At 11.0 cm (4.3 in) in length, it is small and relatively stout. Its body is mostly solid black, with the exception of white discoloration around its pectoral fins and a lateral line of reflective scales. It is most notable for the bioluminescent organs located underneath its eyes, which it uses to find prey, evade predators, and communicate with other members of its species. Like other Beryciformes, its reproduction is oviparous. It has no commercial value, and this combined with its timid, nocturnal nature makes population sizes and trends unknown. It is listed as Least Concern by the International Union for Conservation of Nature (IUCN) due to a wide distribution and lack of known threats.

Taxonomy and phylogeny

Anomalops

Phthanophaneron

Kryptophanaron

Photoblepharon palpebratum

Photoblepharon steinitzi

Phylogenetic tree of Anomalopidae. [2]

The flashlight fish was first described in 1973 by ichthyologists Tokiharu Abe and Yata Haneda, who designated it a subspecies of P. palpebratum. [3] It was reclassified as its own species in 1987 by McCosker and Rosenblatt due to morphological differences and geographic distance between location of specimens. The number of pelvic rays for P. steinitzi is 6 or 7, whereas P. palpebratum will never have 6. Another difference is that the white spot at the upper corner of the opercle in P. palpebratum is smaller and less drastically colored in P. steinitzi, and is sometimes not present at all. [4] Its generic name comes from Greek: "photo" meaning "light" and "blepharon" meaning "eyelash." [5]

As one of the more derived members of Anomalopidae, the flashlight fish shares several synapomorphies with P. palpebratum, Krytophaneron, and Phthanophaneron, including smaller and more numerous scales. Another characteristic which serves as evidence for the cladogram shown left is the method by which certain species "turn off" their light organs. Anomalops has evolved a more mechanically efficient rotation by which the organ is flipped down, whereas the more derived lineages make use of a shutter mechanism by which a lid extends up to cover the light organ. [2]

Description

The flashlight fish has a short, stout, darkly colored body. Its maximum recorded length is 11.0 cm (4.3 in) TL. [5] Its blunt snout and large eyes are characteristic of its family. The pectoral fins are preceded by a white splotch and it may possess a spot of light discoloration at the top of its preopercle, though this is not always the case. This can be used to distinguish it from P. palpebratum in which the spot is larger and whiter. A line of reflective scales run the length of its body from the operculum to the caudal fins. Its most distinctive feature are the bioluminscent organs underneath its eyes, which are white, but emit a blue-green light in the dark. The flashlight fish possesses black lids which slide up to cover the light organs when desired. [4]

Distribution and habitat

The flashlight fish's range is extensive throughout the western Indian Ocean and the Red Sea. With a latitudinal range between 21°S and 45°N, it has been collected from various islands, including Réunion and Comoros, to as far east as Maldives, as well as north to Somalia, Oman, Israel, and Egypt. [5] The typical water temperature of its habitat is 26 °C (79 °F) and salinity is generally around 35 PSU. [6] P. steinitzi typically inhabits caves in and around coral reefs up to 500 m (1,600 ft) in depth by day, ascending to 3–20 m (9.8–65.6 ft) at night to feed. [5] [1]

Biology and ecology

As a nocturnal predator, the flashlight fish generally spends the day hiding in caves and rock crevices. Although it has been observed to share these caves with soldierfish (Myripristinae) and squirrelfish (Holocentrinae), it displays territorial aggression towards other members of its species. Lone fish or mated pairs will defend their territory by swimming aggressively towards an intruding fish and increasing the frequency at which their light organs blink. [7] Evasion of predators is also assisted by its light organs, as the flashlight fish can employ a "blink-and-run" strategy, swimmingly slowly in one direction with its lights on before blinking them off and darting erratically in another direction. [8]

Human interaction

The flashlight fish has little interaction with humans due to its nocturnal nature and lack of commercial value. It may be targeted by local fishermen for use as bait. It was initially listed as Data Deficient by the IUCN, but its status was changed to Least Concern in 2020 after an evaluation found wide geographic distribution and no major threats to its survival. [1]

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Photoblepharon is a genus of poorly understood flashlight fishes found around reefs in the western Pacific Ocean (P. palpebratum) and in the western Indian Ocean (P. steinitzi). Both of its species are nocturnal predators, hiding in caves and crevices during the day and emerging at night to feed. They are small fish, 11.0–12.0 cm (4.3–4.7 in) maximum length, and of little commercial value, although fishermen have been known to use their light organs as bait. Like other anomalopids, they are notable for the white organs containing bioluminescent bacteria underneath their eyes, which, by emitting a blue-green light, allow the fish to search for food, evade predators, and communicate with other fish. Both species have black lids that slide up to cover the organ when the fish does not want to emit light. Although similar in appearance, they can be easily distinguished by the preopercle, which has a medium-sized white spot in P. palpebratum, whereas in P. steinitzi, it is much smaller and much darker, or not present at all. Neither species has been evaluated by the International Union for Conservation of Nature (IUCN) and their nocturnal natures make collection difficult and sightings uncommon.

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Parmops coruscans is a species of flashlight fish, order Beryciformes, native to the Pacific Ocean off the coast of Tahiti and from Fiji to French Polynesia. It is one of two species of Parmops along with P. echinatus, which was discovered off the coast of Fiji. Like other anomalopids, it is notable for the light organs underneath its eyes, which contain bioluminescent bacteria. To cover the organs, it rotates them down while sliding a black lid upward over each eye. The lack of development in its shutter mechanism helps place it between Anomalops and Phthanophaneron on the evolutionary tree.

Protoblepharon mccoskeri, the Taiwanese flashlight fish, is a flashlight fish species found in the Northwest Pacific off of Taiwan's east coast. It can be found as deep as 300m. It was first described in 2012 from a single specimen caught near Taiwan.

Protoblepharon rosenblatti, the Cook Islands flashlightfish, is a species of flashlight fish found in the waters surrounding the Cook Islands. It can reach lengths of up to 22.0 cm (9 in) and can be found as deep as 274 m (900 ft).

References

  1. 1 2 3 Moore, J. (2020). "Photoblepharon steinitzi". IUCN Red List of Threatened Species . 2020: e.T123356073A123356187. doi: 10.2305/IUCN.UK.2020-1.RLTS.T123356073A123356187.en . Retrieved 20 November 2021.
  2. 1 2 Johnson, G. David; Richard H. Rosenblatt (1988). "Mechanisms of light organ occlusion in flashlight fishes, family Anomalopidae (Teleostei:Beryciformes), and the evolution of the group". Zoological Journal of the Linnean Society. 94: 65–96. doi:10.1111/j.1096-3642.1988.tb00882.x.
  3. Abe, Tokiharu; Yata Haneda (1973). "Description of a new fish of the genus Photoblepharon (family Anomalopidae), from the Red Sea". Ministry of Agriculture Bulletin. 60: 57–62.
  4. 1 2 McCosker, John E.; Richard H. Rosenblatt (1987). "Notes on the Biology, Taxonomy, and Distribution of Flashlight Fishes (Beryciformes: Anomalopidae)". Japanese Journal of Ichthyology. 34: 157–164. doi:10.1007/BF02912410.
  5. 1 2 3 4 Froese, Rainer; Pauly, Daniel (eds.) (2017). "Photoblepharon steinitzi" in FishBase . January 2017 version.
  6. "Photoblepharon steinitzi Abe & Haneda 1973". obis.org. Ocean Biodiversity Information System. Retrieved 25 September 2021.
  7. Hellinger, Jens; Peter Jägers; Katharina Spoida; Linda C. Weiss; Melanie D. Mark; Stefan Herlitze (2020). "Analysis of the Territorial Aggressive Behavior of the Bioluminscent Flashlight Fish Photoblepharon steinitzi in the Red Sea". Frontiers in Marine Science. 7 (78). doi: 10.3389/fmars.2020.00078 .
  8. Morin, James G.; Anne Harrington; Kenneth Nealson; Neil Krieger; Thomas O. Baldwin; J. W. Hastings (1975). "Light for All Reasons: Versatility in the Behavioral Repertoire of the Flashlight Fish". Science. 190 (4209): 74–76. doi:10.1126/science.190.4209.74.