Portal field news

Portal field news

in ,

🥾 | <Pyonyang's daily life> Underwater walk at the campsite

Photo (Photo: 2017.7.5)

<Pyonyang's daily life> Underwater walk at the campsite

If you write the contents roughly
Lemon sharks, rays and dolphins swim in the aquarium overlooking 180 degrees overhead.

Underwater walk at the campsite Children are very excited about the tunnel aquarium where you can feel as if you are underwater.Overhead 180 ... → Continue reading

 Choson Sinbo (DIGITAL SINBO)

Choson Sinbo (DIGITAL SINBO) is a comprehensive media about Koreans living in Japan.With a branch office in Pyongyang, the capital of Korea, we provide original content such as the latest news, commentary articles, and videos based on local interviews.

Wikipedia related words

If there is no explanation, there is no corresponding item on Wikipedia.

Lemon shark

Lemon shark(Lemon shark,Negaprion acutidens ) IsGround shark familyBelongs tosharkKind of.Indo-PacificWidely distributed along the coast up to a depth of 92 m in the tropics.大西洋 OfLemon sharkIt has a thick body, a wide head, and a uniform yellow body color, but this species can be distinguished by its strong fin sickle shape.Maximum 3.8m.

Slow movement, mainlyBony fishI eat the.It rarely travels long distances.FetusIt gives birth to 2 or less pups every two years.Although timid, cases of attacks on humans have also been reported.Due to low fertility and mobility, the population is declining due to fishing.IUCN TheConservation statusTheEndangeredAnd


German naturalistEduard RuppelBy 1837 Fische des Rothen MeeresIn ("Red Sea Fish")Carcharias acutidens In the name ofDescriptionWas done. 1940, Australian ichthyologistGilbert Percy WhitleyIs a new genusNegaprion Was founded and this species was transferred.Type specimenWas designated in 1960,JeddahOffshoreRed SeaIt is a 68 cm individual captured in[2].Seed nameacutidens TheLatin Ofacutus(sharp),denseDerived from (teeth).Other English names are broadfin shark, Indian lemon shark, Indo-Pacific lemon shark, or simply lemon shark.[3].

in Japan1981 , Yoshino et al. Confirmed their habitat,Lemon sharkWas given the Japanese name of[4]..Because it is a shark that is often seen in the Okinawa region,Marve carIt is called (meaning shark fin, ordinary shark).

MicrosatelliteFrom DNA, this speciesLemon sharkIt was shown that it diverged 100-140 million years ago.Tethys OceanBy closing, the genus Lemon sharkIndian Ocean大西洋It is thought that it was divided into a group of[5]..As an ancestral lemon shark, with the United StatesPakistanからNegaprion eury bathrodon Teeth have been found[5]..The genus Lemon shark itself has a morphologyMolecular phylogenyBy analysisWhitetip reef sharkWithTiger shark・ ・ Than the basic genus such asCarcharhinusIs placed near[6][7].


Indo-PacificIt is found in a wide range of.In the indian oceanSouth AfricaFrom the Red SeaMauritius-セ ー シ ェ ェ-Eur-lex.europa.eu eur-lex.europa.eu-Indian subcontinentalongSoutheast Asiato.In the PacificTaiwan-フィリピンからNew Guinea-AustraliaNorthern and Pacific Islands (New Caledonia-パラオ-マ ー ャ ル ル-Eur-lex.europa.eu eur-lex.europa.eu-Fiji-バヌアツ-French Polynesia)[1][2]..This species seems to have spread to the central Pacific Ocean along the island, but the population centered on eastern Australia and the population centered on French Polynesia are at least 750 km apart, which is remarkable between them. It is known that there are various genetic differences.For this reason, traveling long distances is considered extremely rare.[5].. in JapanYaeyama IslandsSouthIriomote Island,IshigakijimaSeen at.

continental shelfInhabits the coastal areas of the island shelves andIntertidal zoneCan be seen from to a depth of 92m[8]..I like still water and muddy water,BayWithinEstuary-Lagoon, Or in sandy areas on the outer edge of the reef.Some individuals occasionally appear in the open ocean, and in 1971Sperm whaleAn individual swimming near the corpse of is photographed.The juvenilemangroveCommonly seen in surrounding reefs, the shallow water may cause the dorsal fin to stick out of the water[2][9]..Known as a nurseryShark bayIn Herald Bight, juveniles are common in mangroves shallower than 3 m and open waters,Seaweed Of Posidonia australis Was not seen in places covered with[10].


The body is thick and sturdy, and the head is short and wide.The snout is round and wedge-shaped.nostrilIs small and has a triangular anterior nasal flap.The eyes are small and not.There are short pleats on the corners of the mouth[2]..One dentition is 13–16 on both jaws (usually 14).There is a small median dentition in the center of the jaw.Maxillary teeth have large cusps and wide base, with dents on both sides.The teeth tilt toward the corners of the mouth.Mandibular teeth are similar to maxillary teeth, but thinner and less inclined[9].. Individuals over 1.4 m have fine serrations on their teeth[2].

Fins (especiallyDorsal fin-Pectoral fin-Pelvic fin) Has a stronger sickle shape than the lemon shark.First dorsal fin closer to pectoral fin than pectoral fin.The second dorsal fin is about the same size as the firstAnal finLocated slightly in front of.Pectoral fins are long and wide, starting between the 3rd and 4th gill fissures.There is a strong notch on the trailing edge of the anal fin.Caudal finBase recess facing anterior-posterior[2].Skin teethAre large and overlap, each skin tooth has 3-5 horizontal ridges[8]..The back is uniform tan and the abdomen is pale.Fins are more yellowish[11]..There is a record of up to 3.8m[3], Usually does not exceed 3.1m[9].


It is an inactive species, often swimming slowly just above the seabed or lying on the seabed.Unlike ordinary sandbar sharks, this species can pump water to the gills without swimming.On rare occasions, they may chase food and ascend near the surface of the sea.[2]..Rarely travel long distances[5],Aldabra AtollMore than 90% of individuals were recaptured within 2 km of the original capture site in a ringing survey in[12]..Also in French PolynesiaMooreaSo, it is known that some individuals spend the whole year around the island, but some are mobile and rarely visit the island.[13].

Over 90% of the bait is benthic or coastalBony fishso,Clupeidae-ボ ラ-サ バ・ ・Needlefish family-sillaginoid-Porgies-Ariidae-Triggerfish-Parrotfish-PorcupinefishEtc. are included.RarelyCephalopod,crustacean, In large individualsWhiptail stingrayAlso known to eat ya[2][12][14][15]..This species is preyed on by large sharks[8].ParasiteAs,Tapeworm OfParaorygmatobothrium arnoldi [16]-Pseudogrillotia spratti [17]-Phoreiobothrium perilocrocodilus [18]-Platybothrium jondoeorum [19]It has been known.Also, lie down on the seabedHonsome Wake BellaIt has been recorded to encourage cleaning behavior.There was also behavior in which Bella held her breath open for 150 seconds to bring her closer to her mouth and gills.[20]

Like other sandbar sharksFetusAnd grew upEmbryo TheYolk sacTheplacentaConvert to.The placenta is formed at 4 months of gestation, with traces of the external gills still remaining.Females give birth in shallow nurseries every two years.Gestation period is 2-10 months, number of pups is 11-1 (usually 13-6)[2][12]..Unlike the lemon shark, it does not show the nostalgia of returning to the sea area where it was born.[5]..Births occur in Madagascar and Aldabra from October to November and in French Polynesia in January.Non-pregnant females at the same timeovulation-MatingI do.45-80 cm at birth[2][12]..Growth is slow, around 12.5-15.5 cm / year.2.2-2.4m for both males and femalesSexual maturityTo[8].

Relationship with people

Several non-provocative attacks have been reported.It is considered potentially dangerous due to its size and tooth shape, and is known to react quickly and violently when a person is provoked by contact or attack.Once hostile, it clung to it, and in one case hunted the diver to the top of the coral and swam around it for several hours.However, divers' observations have reported that they are usually timid and reluctant to approach, even in the presence of food.They often swim away before they are in the diver's field of view.There are also reports that young individuals are more aggressive than adults.[2]..On Moorea, by feedingEco tourismIs subject to[13].

Easy to breed,aquariumBut bred[2].Okinawa Churaumi AquariumThen.2008 On July 7, we succeeded in giving birth to a lemon shark in an aquarium for the first time in Japan.Breeding AwardHas been awarded.

IUCNAs a wholeConservation statusTheVulnerableAndGillnet,LonglineCaught in[1], Meat is sold raw, dried and salted.Shark fin,Cod liver oilIs also used[2]..Regional due to low fertility and mobilityoverfishingVery weak to.It is becoming rare in Southeast Asia due to the expansion of unregulated fishing, and it is locallyEndangeredIt is evaluated as.In this areaWater pollution,Explosive fishing methodHabitat destruction due to mangrove logging is also serious.India,Kingdom of ThailandIt appears to be extinct in some parts of the country and was once abundantIndonesiaIt is no longer seen in the market.In australiaBycatchOnly a small number are caught byMild concernIs said to be[1].

in JapanYaeyama IslandsIt is found only in some tropical waters and is not important for fisheries.In Okinawa, fishermen dislike it because it is attracted to and devoured by fish caught in nets and baskets.


  1. ^ a b c d Pillans, R. (2003). "Negaprion acutidens". IUCN Red List of Threatened Species. version 2008. International Union for Conservation of Nature.Retrieved January 2009, 5.
  2. ^ a b c d e f g h i j k l m Compagno, LJV (1984). Sharks of the World: An Annotated and Illustrated Catalog of Shark Species Known to DateRome: Food and Agricultural Organization. Pp. 517–518. ISBN 92-5-101384-5 
  3. ^ a b Froese, Rainer and Pauly, Daniel, eds. (2009). "Negaprion acutidens" in FishBase. August 2009 version.
  4. ^ Tetsuo Yoshino, Wataru Hiramatsu, Minoru Toda and Senzo Uchida (1981). “New Records of Two Sharks, Nebrius concolor and Negaprion acutidens from Japanese Waters ”. Bulletin of the College of Science. University of the Ryukyus 32: 37-46. 
  5. ^ a b c d e Schultz, JK, KA Feldheim, SH Gruber, MV Ashley, TM McGovern and BW Bowen (2008). “Global phylogeography and seascape genetics of the lemon sharks (genus) Negaprion)”. Molecular Ecology 17 (24): 5336–5348. two:10.1111 / j.1365-294X.2008.04000.x. PMID 19121001. http://www2.hawaii.edu/~jschultz/docs/Schultz_et_al_2008_lemon_sharks.pdf. 
  6. ^ Carrier, JC, JA Musick and MR Heithaus (2004). Biology of Sharks and Their Relatives.CRC Press. Pp. 52, 502. ISBN 0-8493-1514-X 
  7. ^ Naylor, GJ; Caira, JN; Jensen, K .; Rosana, KA; Straube, N .; Lakner, C. (2012). “Elasmobranch phylogeny: A mitochondrial estimate based on 595 species”. In Carrier, JC; Musick, JA; Heithaus, MR, eds. The Biology of Sharks and Their Relatives (second ed.). CRC Press. Pp. 31–57. ISBN 1-4398-3924-7. http://prosper.cofc.edu/~sharkevolution/pdfs/Naylor_et_al_Carrier%20Chapter%202.pdf. 
  8. ^ a b c d Bester, C. Biological Profiles: Sicklefin Lemon Shark. Florida Museum of Natural History Ichthyology Department. Retrieved on August 24, 2009.
  9. ^ a b c Randall, JE and JP Hoover (1995). Coastal Fishes of Oman. University of Hawaii Press. P. 35. ISBN 0-8248-1808-3 
  10. ^ White, WT and IC Potter (2004). “Habitat partitioning among four elasmobranch species in nearshore, shallow waters of a subtropical embayment in Western Australia”. Marine Biology 145 (5): 1023–1032. two:10.1007 / s00227-004-1386-7. 
  11. ^ Randall, JE, GR Allen, and RC Steene (1997). Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press. P. 22. ISBN 0-8248-1895-4 
  12. ^ a b c d Stevens, JD (July 23, 1984). “Life-History and Ecology of Sharks at Aldabra Atoll, Indian Ocean”. 222 (1226): 79–106. two:10.1098 / rspb.1984.0050. 
  13. ^ a b Buray, N., J. Mourier, E. Clua and S. Planes. (2009). "Population size, residence patterns and reproduction of a sicklefin lemon shark population (Negaprion acutidens) Visiting a shark-feeding location at Moorea Island, French Polynesia. "The 11th Pacific Science Inter-Congress in conjunction with the 2nd Symposium on French Research in the Pacific. March 2–9, 2009.
  14. ^ White, WT, ME Platell and IC Potter (2004). “Comparisons between the diets of four abundant species of elasmobranchs in a subtropical embayment: implications for resource partitioning”. Marine Biology 144 (3): 439–448. two:10.1007 / s00227-003-1218-1. 
  15. ^ Salini, JP, SJM Blaber and DT Brewer (1990). “Diets of piscivorous fishes in a tropical Australian estuary, with special reference to predation on penaeid prawns”. Marine Biology 105 (3): 363–374. two:10.1007 / BF01316307. 
  16. ^ Ruhnke, TR and VA Thompson (2006). “Two New Species of Paraory gmatobothrium (Tetraphyllidea: Phyllobothriidae) from the Lemon Sharks Negaprion brevirostris and Negaprion acutidens (Carcharhiniformes: Carcharhinidae) ”. Comparative Parasitology 73 (1): 35–41. two:10.1654/4198.1. 
  17. ^ Beveridge, I. and JL Justine (2007). “Paragrillotia apecteta n. sp. and redescription of P. spratti (Campbell & Beveridge, 1993) n. comb. (Cestoda, Trypanorhyncha) from hexanchid and carcharhinid sharks off New Caledonia ”. Zoosystema 29 (2): 381–391. 
  18. ^ Caira, JN, C. Richmond and J. Swanson (2005). “A revision of Phoreiobothrium (Tetraphyllidea: Onchobothriidae) with descriptions of five new species ”. Journal of Parasitology 91 (5): 1153–1174. two:10.1645 / GE-3459.1. PMID 16419764. 
  19. ^ Healy, CJ (October 2003). “A revision of Platybothrium Linton, 1890 (Tetraphyllidea: Onchobothriidae), with a phylogenetic analysis and comments on host-parasite associations ”. Systematic Parasitology 56 (2): 85–139. two:10.1023 / A: 1026135528505. PMID 14574090. 
  20. ^ Keyes, RS (1982). “Sharks: an unusual example of cleaning symbiosis”. Copeia 1982 (1): 227–229. two:10.2307/1444305. 

180 degrees overhead


Back to Top