SIGANIDAE

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SIGANIDAE

• by
• KAMOLRAT PHUTTHARAKSA

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Siganids are small to moderate size, primarily
herbivorous fishes found in a variety of habitats
including coral reefs, sea grass beds and
estuaries.Some species have commercial value as
a food fish, and some have been considered for
aquaculture.
RABBITFISHES
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Review of Morphological features

• General appearance
• Larvae are initially elongate, but become
  moderate in depth before flexion. They are
  laterally compressed, and have 22-24 myomeres.
• The head is initially moderate in size and round,
  and the snout is blunt by flexion. The eye is
  large in preflexion larvae but moderate to large
  following flexion.

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• Head spination
• Larvae develop spines along both preopercular
  borders these remain small to moderate. Serrate
  ridges form shortly thereafter along top of the
  head and leterally on the snout.
• During and following flexion small spines or
  serrate ridges from on the supraocular, pterotic,
  posettemporal, suparcleithrum, angular,
  infraorbital and lateral etmoid.
• Pigmentation
• Larvae have pigment on the dorsal surface of the
  gut and along the ventral midline of the tail.
  The number of malanophores in the series
  decreases with development until flexion.

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Meristic Character

D A P1 P2 C Vertebrae
Siganus XIII-XIV, 10 VII, 9-10 15-19 I, 3, I 98 101424
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Family SiganidaeGenus Siganus

• Sampling Location
• Gulf of Thailand Palavan
• Sampling Gear Bongo net
• Stage Flexion (Gulf of Thailand)
  Postflexion (Palavan)

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Measurements
(mm)
Stage BL HL ED SnL PAL BD
Flexion 5.0 1.5 0.6 0.3 2.4 1.8
Postflexion 10.0 3.1 1.2 0.9 4.7 3.4
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Counts
Stage D A P1 P2 C Myomeres
Flexion IIII - - I - 23
Postflexion XIV, 10 VII, 9 15 I,3,I 23
C 98 (Leis and Carson-Ewart, 2000)
The body depth moderate 30BL, gut coiled and
compact early, anus open 50 BL.
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Flexion

• The body depth moderate 30BL, gut coiled and
  compact early.
• Larvae have supraoccipital and frontal, serrate
  ridges form shortly thereafter along the top of
  the head, supracleithral, and laterally on the
  nasal, and both preopercular
• Larvae have serrate ridges anterior pelvic
  girdle. Dorsal fin are 5 spine, anterior of the
  second spine of dorsal and spine of pelvic fin
  have serrate.

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Flexion

• Dorsal and anal fin still undeveloped, Caudal fin
  appear soft rays
• Pigment appear on the brain and the head, on gut,
  membrane of dorsal fin and pelvic fin, and anal
  fin base.

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Flexion
Postflexion