Octavo-lateralis system

The Lateral Line Organs of Four
Deep-Sea Fish
THE UNIVERSITY
OF QUEENSLAND
A U S T R A L I A
Justin Marshall
Kylie Greig
Sensory Neurobiology
Group SBMS, QBI

• Kylie Greig
Acknowledgements
• ARC Linkage, NOAA, NSF, BBSRC,
NERC, WID
• Harbour Branch, RRS Discovery,
Challenger, DeepOcean Quest
• Ted Pietch, John Paxton, Pete Herring,
Nigel Merrett
• Edie Widder – some photographs

Deep Australia Project

Talk Plan
• The Fish
• Methods – gentle capture, CCE or Subs
• Lateral Line Sensory System
• Anglerfish
• Anoplogaster
• Whalefish
• Eels
• Sensory Systems in the Deep Ocean

Talk Plan
• The Fish
• Methods – gentle capture, CCE or Subs
• Lateral Line Sensory System
• Anglerfish
• Anoplogaster
• Whalefish
• Eels
• Sensory Systems in the Deep Ocean

Himantalophus groenlandicus Ditropichthys storei
Saccopharynx sp. Anoplogaster cornuta

Developing anglerfish comparison story
Show movie

Talk Plan
• The Fish
• Methods – gentle capture, CCE or Subs
• Lateral Line Sensory System
• Anglerfish
• Anoplogaster
• Whalefish
• Eels
• Sensory Systems in the Deep Ocean

The Mother-Tucker

The Father-Tucker
Net systems in Australia
Later in the year.
Closing cod-end critical

Deep-Australia

MV Alucia
Deep-Australia

Talk Plan
• The Fish
• Methods – gentle capture, CCE or Subs
• Lateral Line Sensory System
• Anglerfish
• Anoplogaster
• Whalefish
• Eels
• Sensory Systems in the Deep Ocean

Fluid-filled canals and single or
groups of receptors over skin
Fluid-filled canals
lie just below the
skin of the head
and along the
lateral flanks

Types of neuromasts
• Modifications of 2 basic types (free and canal
neuromasts)
Ampullae of Lorenzini (modified neuromast)
found in elasmobranchs and some bony fishes

Neuromasts and hair cells

Neuromasts and hair cells
• Neuromasts are
comprised of
sensory hair cells
• The hair cells have
intermingled groups
of opposing
polarities (~ hair cells
in the ear)
• Towards kinocilium
(excitation), towards
stereocilia
(inhibition)
• Transduction of
mechanical energy to
electrical energy

Hair cells in action

Lateral line hair cell orientation
gives directional sensitivity

Lateral line hair cell orientation
gives directional sensitivity

Lateral line hair cell orientation
gives directional sensitivity

Talk Plan
• The Fish
• Methods – gentle capture, CCE or Subs
• Lateral Line Sensory System
• Anglerfish
• Anoplogaster
• Whalefish
• Eels
• Sensory Systems in the Deep Ocean

Himantalophus groenlandicus

Himantalophus groenlandicus

Himantalophus groenlandicus

Himantalophus groenlandicus female
Morphometrics of neuromasts of Himantalophus groenlandicus female.
Himantalophus
groenlandicus female
Shape of neuromasts
including supporting cells
Canal
Neuromast
s
Nil Diamond
Superficial Neuromasts
Shape of sensory plate Nil Oval with long axis perpendicular to
neuromasts shape
Sensory plate diameter,
µm
Major axis
Minor axis
Number of hair cells per
neuromasts
Number of hairs per hair
cell
Nil 23µm
(range = 15.6µm-29.8µm) N=10
15.5µm
(range = 10µm-19.5µm) N=10
Nil 85 (range = 44-116) N=14
Nil 30 (range 20-37) N=20
Length of Kinocilium* Nil 6.7µm (range = 3.0µm-16.7µm) N=20
Length of Stereocilia* Nil 11.9µm (range = 0.5µm- 7.3µm) N=24
Direction of sensitivity Nil Perpendicular to the long axis of the
neuromast, therefore along the lateral
line.

Distribution of superficial neuromasts along lateral lines in Himantalophus groenlandicus female.
Lateral Line locations
Number of superficial neuromasts per side
Specimen 1
Standard Length 44cm –adolescent female
Supraorbital (face) 39
Infraorbital (cheek) 32
Supratemporal (top head) 25
Preopercular (operculum) 44
Mandibular (lower jaw) 47
Trunk (body) 31
Line b/n infraorbital & mandibular 13
Total 223

Anoplogaster cornuta

Buccal array - undescribed
Good for prey detection?
Different organ morphologies?

Sensitivity directions
Different organ morphologies?

Sensitivity directions
Different organ morphologies?

Ditropichthys storei

Ditropichthys storei

John Paxton

Saccopharynx sp.

Saccopharynx sp.
Free standing organs
NOT electrosensory
Cupula

Cupula

Free standing head
papillae
?

Saccopharynx sp.
Morphometrics of Saccopharynx sp. Neuromasts
Saccopharynx sp.
Shape of neuromasts
including supporting cells
Canal
Neuromast
s
Nil Oval
Superficial Neuromasts
Shape of sensory plate nil Narrow oval perpendicular to
neuromasts shape
Sensory plate diameter,
µm
Major axis
Minor axis
Number of hair cells per
neuromasts
Number of hairs per hair
cell
Nil 117µm
(range = 218µm-52µm) N=12
22.5µm
(range = 42µm-16µm) N=11
Nil 150-200 N=2
Nil 25-40 N=20
Length of Kinocilium* Nil 4.5µm (range = 8.0µm-2.2µm) N=11
Length of Stereocilia* Nil 1.0µm (range = 2.1µm- 0.3µm) N=47
Direction of sensitivity Nil Across the oval sensory plate and
therefore along the lateral line.

Distribution of superficial neuromasts along lateral lines in Saccopharynx sp.
Lateral Line locations
Number of superficial neuromasts per side
Specimen 1 Specimen 2
Standard Length 18cm 45cm
Supraorpital (face) 17 12
Infraorbital (cheek) 7 12
Supratemporal (top head) 7 12
Preopercular (operculum) 13 15
Mandibular (lower jaw) ? damaged 0
Trunk (body) 151 153
Total 213+ 204
Note that the neuromasts numbers are similar independent of animal size.
We would like more eels

Eurypharynx pelicanoides

Eurypharynx pelicanoides

Talk Plan
• The Fish
• Methods – gentle capture, CCE or Subs
• Lateral Line Sensory System
• Anglerfish
• Anoplogaster
• Whalefish
• Eels
• Sensory Systems in the Deep Ocean

Conclusions
• Through gentle capture and rapid EM
fixation on board ship, ultrastructure.
• 2 species with enlarged canal systems and free
standing papillae
• 2 species with just free standing organs and no
canals
• The directions of sensitivity and comparative
morphology of these organs enables some
comfortable conclusions regarding function.
• Need behaviour! This is no longer a dream….

Thanks for listening!