Overview

Distribution

Range Description

Eastern Indian Ocean: known from few specimens collected from four fish landings sites in southern Indonesia (Palabuhanratu in West Java (06°59' S, 106°32' E), Cilacap in Central Java (07°44' S, 109°00' E), Kedonganan in Bali (08°45' S, 115°10' E), and Tanjung Luar in Lombok (08°48' S, 116°28' E)) (Last and White 2008).
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Off southern Indonesia.
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Indian Ocean: Indonesia. Occurs off southern Indonesia. Palabuhanratu in West Java, Cilacap in Central Java, Kedonganan in Bali, and Tanjung Luar in Lombok. Depth information not known.
  • Last, P.R. and W.T. White 2008 Three new angel sharks (Chondrichthyes:Squatinidae) from the Indo-Australian region. Zootaxa 1734:1-26. (Ref. 74939)
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Physical Description

Size

Max. size

134 cm TL (male/unsexed; (Ref. 74939)); 47.1 cm TL (female)
  • Last, P.R. and W.T. White 2008 Three new angel sharks (Chondrichthyes:Squatinidae) from the Indo-Australian region. Zootaxa 1734:1-26. (Ref. 74939)
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Diagnostic Description

Body strongly depressed anteriorly, firm; trunk strongly depressed, almost ray-like, deepestover abdomen; not tapering abruptly at pelvic-fin insertion, tail strongly depressed, even at origin of caudal fin. Abdomen moderately elongate. Head broad, extended laterally, strongly depressed; oval in cross-section; subcircular, with truncate anterior margin when viewed from above. Mouth large, terminal. Dermal denticles covering entire dorsal surface of body; less dense, absent on posterior borders of fins (Ref. 74939).
  • Last, P.R. and W.T. White 2008 Three new angel sharks (Chondrichthyes:Squatinidae) from the Indo-Australian region. Zootaxa 1734:1-26. (Ref. 74939)
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Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
This species is demersal, presumably occurring in deeper waters, probably on the continental slope. Detailed information on the depth range of this species is not available (all known specimens were collected from fish landings sites) (Last and White 2008). Presumably viviparous, with yolk-sac dependency (White et al. 2006). One female measured 47.1 cm total length (TL) and three adult males measured 125.2-134.1 cm TL (Last and White 2008).

Systems
  • Marine
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Environment

benthopelagic; marine
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Molecular Biology and Genetics

Molecular Biology

Barcode data: Squatina legnota

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There are 2 barcode sequences available from BOLD and GenBank.

Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.

See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

ACCCTTTACTTAATCTTCGGTGCATGAGCAGGAATAGTAGGTACTGCCCTA---AGTTTACTTATCCGAGCAGAATTAAGCCAGCCCGGAACACTCCTTGGGGAC---GATCAAATTTACAATGTAATCGTTACTGCCCACGCTTTAGTAATAATCTTTTTTATAGTAATGCCAATTATAATCGGAGGGTTTGGAAATTGATTAGTTCCCTTAATA---ATTGGCGCGCCAGATATAGCTTTCCCACGAATAAATAATATAAGTTTCTGACTTTTACCTCCTTCCCTACTTTTACTACTTGCCTCAGCCGGAGTTGAAGCAGGGGCCGGCACTGGTTGAACAGTTTACCCTCCTCTTGCAGGAAATTTAGCTCATGCTGGAGCATCAGTAGATTTA---GCAATTTTTTCCTTACATTTAGCTGGTATCTCTTCAATCCTAGCCTCTATTAACTTCATTACAACCATTATTAATATAAAACCCCCAGCTATTTCCCAATATCAAACACCACTCTTTGTTTGATCAATCCTTGTAACTACTGTCCTTCTCCTCCTTTCTCTCCCAGTCCTCGCAGCT---GCAATCACAATATTATTAACCGACCGAAACCTTAACACAACATTTTTTGACCCTGCAGGAGGTGGGGACCCAATCCTTTATCAACACCTT------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------TTC
-- end --

Download FASTA File

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Statistics of barcoding coverage: Squatina legnota

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 4
Species With Barcodes: 1
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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
DD
Data Deficient

Red List Criteria

Version
3.1

Year Assessed
2009

Assessor/s
Valenti, S.V. & White, W.

Reviewer/s
Simpfendorfer, C. & Fowler, S.L. (Shark Red List Authority)

Contributor/s

Justification
Squatina legnota is a moderately large-bodied angel shark, known only from few specimens collected at fish landing sites in southern Indonesia. Although no detailed depth information is available, based on the species composition of the catches including the observed specimens, it is likely a slope dwelling species. It is captured rarely by demersal longliners and is retained and utilised for its meat and fins. Deepwater fishing is relatively restricted at this stage in Indonesia, but if deepwater fisheries expand in this area in the future this assessment would need to be revisited, as many species of angel shark have proved particularly vulnerable to population depletion. More information is required on this species and further development of deepwater fisheries in Indonesia should be monitored.
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Population

Population
Known from few specimens (Last and White 2008).

Population Trend
Unknown
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Threats

Major Threats
This species is a rare utilised bycatch of demersal longline fisheries operating in continental shelf and upper slope waters (White et al. 2006). Possibly an Indonesian endemic, as has not been recorded from adjacent regions. Only limited deepwater fishing currently takes place in Indonesia but if this was to change then this species may qualify for a threat category. Other angel shark populations (e.g. S. squatina, S. argentina) have proved particularly vulnerable to fishing pressure due to their low reproductive potential, vulnerability to trawl and gillnet fishing gear and low potential for re-colonisation (due to their sedentary habit) (Gaida 1997, ICES 2004, Morey et al. 2006, Vooren and Klippel 2005). Monitoring of the deepwater fisheries of Indonesia should be established and maintained.
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Data deficient (DD)
  • IUCN 2006 2006 IUCN red list of threatened species. www.iucnredlist.org. Downloaded July 2006.
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Management

Conservation Actions

Conservation Actions
No measures in place.

Catch levels need to be accurately quantified and monitored. Research is also required on this species' full distribution, habitat and life-history parameters.
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Wikipedia

Indonesian angelshark

The Indonesian angelshark (Squatina legnota) is a rare species of angel shark, family Squatinidae, known only from a few specimens collected from fish landing sites in southern Indonesia. It is thought to inhabit the deep waters of the continental slope. Reaching at least 1.34 m (4.4 ft) long, this species has a flattened, ray-like shape and a well-developed tail and caudal fin. It is characterized by the absences of fringes on its nasal barbels and thorns down the midline of its back, as well as by its relatively plain grayish-brown dorsal coloration with dark saddles beneath the dorsal fin bases and a black leading margin on the underside of the pectoral fins. The International Union for Conservation of Nature (IUCN) presently lacks sufficient information to assess the conservation status of this species.

Taxonomy and phylogeny[edit]

The Indonesian angelshark was described by Commonwealth Scientific and Industrial Research Organisation (CSIRO) researchers Peter Last and William White in a 2008 volume of the scientific journal Zootoxa, based on specimens found at several Indonesian fish landing sites. One of the specimens, a 47 cm (19 in) long female from the Cilacap landing site in central Java, was designated the holotype. The specific epithet comes from the Greek legnotos ("having a colored border"), in reference to the dark leading margins of the pectoral fins.[2]

Björn Stelbrink and colleagues' 2010 phylogenetic analysis, based on mitochondrial DNA, found that the sister species of the Indonesian angelshark is the Taiwan angelshark (S. formosa); the two were the closest genetically of all the species examined. The pair additionally formed a clade with the Japanese angelshark (S. japonica) and the ocellated angelshark (S. tergocellatoides), both also Asian species.[3]

Distribution and habitat[edit]

The known specimens of the Indonesian angelshark have come from fish landing sites at Palabuhanratu in West Java, Cilacap in Central Java, Kedonganan in Bali, and Tanjung Luar in Lombok. Therefore, specific information on its preferred natural habitat is unavailable, though it is probably bottom-dwelling in the deeper waters of the continental slope.[1]

Description[edit]

The largest known Indonesian angelshark specimen measured 1.34 m (4.4 ft) long. As in all angel sharks, it has a flattened body with greatly enlarged pectoral and pelvic fins. The broad, flattened head has a very short, blunt snout and small, widely spaced eyes placed somewhat on top. The eyes are followed by much larger, crescent-shaped spiracles. The nostrils are large and preceded by well-developed flaps of skin that reach the mouth; each flap bears two prominent barbels, which are smooth rather than fringed. The capacious, gently curved mouth is placed at the front of the head. There are long, deep furrows extending from the mouth corners onto and away from the lower jaw. The teeth number around 18 rows in both jaws; each is small and dagger-like, with a single sharp cusp. The five pairs of gill slits are long and placed on the sides of the head.[2]

The pectoral fins are angular, with the anterior lobes of their bases free from the head, and their outer tips forming an angle of slightly under 120°. The tips of the pelvic fins are rounded; males have thick claspers. The two dorsal fins are close in shape and size, with rounded to angular apexes and slightly convex trailing margins. The first dorsal originates over the pelvic fins rear tips, and the second dorsal is placed close to the first. There is no anal fin. The tail is rather long, with the caudal peduncle moderately flattened and expanded laterally into keels. The lower lobe of the short and triangular caudal fin is larger than the upper, and there is a notch in the upper lobe trailing margin. The dorsal surface is covered by small, roughly conical dermal denticles. This species is grayish brown above, darkening around the eyes and on the snout and becoming translucent at the trailing fin margins. There are blackish saddle markings below the dorsal fin bases, and sometimes also large, dark blotches and "eyespots" scattered over the dorsal surface. The underside is almost completely white, with a black leading margin on the pectoral fins.[2]

Biology and ecology[edit]

Little is known of the Indonesian angelshark's natural history. It is presumably aplacental viviparous like other members of its family. The smallest male specimen, an adult, measured 1.25 m (4.1 ft) long.[1]

Human interactions[edit]

The Indonesian angelshark is rarely caught incidentally on demersal longlines and marketed for meat and fins. If the presently limited Indonesian deepwater fisheries were to expand, this species may be threatened as other angel shark species have shown themselves to be particularly susceptible to fishing depletion. Pending more data, the International Union for Conservation of Nature has listed this shark under Data Deficient.[1]

References[edit]

  1. ^ a b c d Valenti, S.V. and W. White (2008). "Squatina legnota". IUCN Red List of Threatened Species. Version 2010.4. International Union for Conservation of Nature. Retrieved December 11, 2010. 
  2. ^ a b c Last, P.R. and W.T. White (March 28, 2008). "Three new angel sharks (Chondrichthyes: Squatinidae) from the Indo-Australian region". Zootaxa 1734: 1–26. 
  3. ^ Stelbrink, B., T. von Rintelen, G. Cliff, and J. Kriwet (2010). "Molecular systematics and global phylogeography of angel sharks (genus Squatina)". Molecular Phylogenetics and Evolution 54: 395–404. doi:10.1016/j.ympev.2009.07.029. PMID 19647086. 
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