Overview

Brief Summary

Introduction

Species of Helicocranchia are small, oceanic squid (100 mm ML) characterized by having a very large funnel and small paddle-like fins that attach to a portion of the gladius that rises above the muscular mantle. They exhibit a gradual ontogenetic descent from near-surface waters as paralarvae to lower mesopelagic depths as near-adults.

Brief diagnosis:

A taoniin...

  • with exceptionally large funnel relative to head and arms.
  • with fins which project dorsally in advance of mantle apex.

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Comprehensive Description

Characteristics

  1. Tentacles
    1. Clubs with suckers only.
    2. Tentacular stalks with two series of suckers and pads nearly to stalk base.

  2. Funnel
    1. Funnel valve absent.
    2. Funnel organ: Dorsal pad with 3 slender papillae.
    3. Funnel extremely large.

      Figure. Side view of H. pfefferi, showing the large funnel and small arms. Photograph by M. Vecchione.

  3. Mantle
    1. Tubercles absent from funnel-mantle fusion.

  4. Fins
    1. Fins paddle shaped.
    2. Fins insert on short rostrum of gladius which projects dorsally in advance of mantle apex (photographs below).*

      Figure. Views of the mantle tip and fins of H. pfefferi. Left - Dorsolateral view, Hawaiian waters. Photograph by R. Young. Right - Lateral view, N. W. Atlantic. Photograph by M. Vecchione.

  5. Photophores
    1. Single ocular photophore. (Difficult to detect in some species.)
    2. Arm-tip photophores absent.

      Figure. Left - Posterior and lateral views of the ocular photophore of H. papillata, 60 mm ML. Drawings from Voss, 1980, p. 383. Right - Ventral view of an eye of H. pfefferi showing the yellowish ocular photophore on the medial face of the eye, 35 mm ML. Photographed aboard the R/V G. O. SARS, Mar-Eco cruise, central North Atlantic by R. Young.

*Unique in family.

Comments

One of the most distinctive features of this genus is the extremely large funnel that extends well beyond the beaks. This feature, which recalls the large snout of a pig, gives the squid its common name. Characteristics are from Voss (1980).

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Distribution

Vertical distribution

The distribution of Helicocranchia pfefferi from Hawaiian waters shows a clear pattern of ontogenetic descent with squid occurring in progressively deeper water as they get larger. Diel vertical migration does not seem to occur in this species. The dominance of nighttime captures for young stages is a result of the low sampling effort in shallow depths during the daytime and doesn't indicate the daytime absence of small squid at these depths.

Figure. Vertical distribution chart of H. pfefferi, Hawaiian waters. Captures were made with both open and opening/closing trawls. Bars- fishing depth-range of opening/closing trawl. Circle- Modal fishing depth for either trawl. Blue-filled circles- Night captures. Yellow-filled circles- Day capture. Chart modified from Young (1978).

In the Atlantic Lu and Clarke (1975) show a similar vertical distribution pattern for Helicocranchia pfefferi. Most captures at less than 30 mm ML were made between 100 and 200 m. Around 30 mm ML an ontogenetic descent began although their largest specimen (49 mm ML) was taken between 300 and 400 m. Presumably the size/depth trend would continue for larger individuals.

Geographical distribution

Species occur throughout the world's tropical and subtropical oceans and, in the Atlantic Ocean, in north temperate waters (Voss, 1992).

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Ecology

Habitat

Bathypelagic
  • Census of Marine Zooplankton, 2006. NOAA Ship Ronald H Brown, deployment RHB0603, Sargasso Sea. Peter Wiebe, PI. Identifications by L. Bercial, N. Copley, A. Cornils, L. Devi, H. Hansen, R. Hopcroft, M. Kuriyama, H. Matsuura, D. Lindsay, L. Madin, F. Pagè
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

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Depth range based on 209 specimens in 5 taxa.
Water temperature and chemistry ranges based on 199 samples.

Environmental ranges
  Depth range (m): 30 - 2441
  Temperature range (°C): 3.278 - 23.252
  Nitrate (umol/L): 0.125 - 39.064
  Salinity (PPS): 34.110 - 36.622
  Oxygen (ml/l): 0.333 - 6.046
  Phosphate (umol/l): 0.030 - 3.143
  Silicate (umol/l): 0.798 - 80.938

Graphical representation

Depth range (m): 30 - 2441

Temperature range (°C): 3.278 - 23.252

Nitrate (umol/L): 0.125 - 39.064

Salinity (PPS): 34.110 - 36.622

Oxygen (ml/l): 0.333 - 6.046

Phosphate (umol/l): 0.030 - 3.143

Silicate (umol/l): 0.798 - 80.938
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

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Life History and Behavior

Life Cycle

Life History

The large funnel is present in the paralarva and makes generic identification of paralarvae easy. There is a near absence of an optic stalk making the eyes nearly sessile.

Figure. Dorsal and ventral views of a paralarva of H. pfefferi, 3.4 mm ML, Hawaiian waters. Drawings by R. Young. The scale bar is 1 mm.

With increased age and depth of occurrence, Helicocranchia, becomes reddish in color probably as they start to mature sexually. Near sexual maturity many cranchiids apparently lose their tentacles. The insitu ROV images on the right below show that loss of tentacles is, indeed, normal.

Figure. Left - Side view of H. pfefferi, central North Atlantic, 63 mm ML. Note the color and the absence of tentacles. Photographed aboard the MarEco cruise of the R/V G.O. SARS by R. Young. Right - Insitu photographs of the same individual of Helicocranchia sp, anterolateral views, from an ROV photographed floating in front of oil pumping equipment in the Gulf of Guinea at a depth of 1015 m (SERPENT project). Arrow in upper photograph points to stub of tentacle.

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Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Helicocranchia sp.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

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Statistics of barcoding coverage

Barcode of Life Data Systems (BOLD) Stats
                                        
Specimen Records:3Public Records:1
Specimens with Sequences:2Public Species:1
Specimens with Barcodes:2Public BINs:1
Species:2         
Species With Barcodes:2         
          
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

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Barcode data

Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

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Locations of barcode samples

Collection Sites: world map showing specimen collection locations for Helicocranchia

Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

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Wikipedia

Helicocranchia

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Source: Wikipedia

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