Overview

Brief Summary

Introduction

H. heteropsis is similar to its closest relative, H. meleagroteuthis, in the uniform, dense pattern of complex photophores on the head, arms IV and the mantle but lacks tubercules. This species is common off the coast of Southern California (USA) and has been observed from submersibles many times. It is lethargic in response to disturbance by an ROV; movements are slow and deliberate, even when jetting, inking is rarely observed (Hunt, 1966). The geographical distribution is unusual in that two separate populations exist one in the North Pacific and one in the South Pacific (antitropical distribution). It is found in temperate regions on the eastern side of the Pacific. Off southern California it occupies mesopelagic depths during the day and migrates vertically at night, presumably to feed. Maximum recorded size is 132 mm ML (Voss, et al., 1998).

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Comprehensive Description

Nomenclature

The holotype (by subsequent designation) is no longer extant. The single paratype, a female, exists at the California Academy of Sciences, San Francisco (Sweeney et al., 1988).

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Characteristics

  1. Head
    1. Beaks: Descriptions can be found here: Lower beak; upper beak.

  2. Tubercles
    1. Absent

Comments

More details of the description can be found here.

Species of the meleagroteuthis-group are distinguished by the following characteristics:

  1. Photophores
    1. In 8-10 series on arm IV base.
    2. Usually 19-22 photophores on right eyelid.
    3. Compound photophores of uniform size, small and densely packed on anterior 3/4 of ventral mantle.

H. heteropsis is easily separated from its closest relative, H. meleagroteuthis, by the absence of tubercles.

The above information is taken from Voss (1969) and Voss, et al. (1998).

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Distribution

Vertical distribution

These data from a vertical distribution study off Southern California shows that H. heteropsis migrates vertically from over 400 m during the day into the upper 400 m at night (Roper and Young, 1975.).

Figure. Chart of the vertical distribution of H. heteropsis, California waters. Captures were made with open 3-m trawls. Blue color - Night captures. Yellow color - Day captures. Lighter hues - Correction factor to adjust for unequal trawling time at each depth. Chart modified from Roper and Young (1975).

Geographical distribution

Type locality: Eastern North Pacific, off Santa Barbara Island. H. heteropsis is common in the California Current system between 24° and 45° N. It is also common in the Peru-Chile Current system between 30° and 36° S. In tropical waters it is generally replaced by its close relative, H. meleagroteuthis, although a single record (00° 38'S, 89° 29'W) is known from equatorial waters (Voss, et al., 1998).

Figure. Chart of the geographical distribution of H. heteropsis. Modified from Voss et al. (1998).

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Ecology

Habitat

mesopelagic
  • UNESCO-IOC Register of Marine Organisms
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 10 specimens in 1 taxon.
Water temperature and chemistry ranges based on 6 samples.

Environmental ranges
  Depth range (m): 32 - 711
  Temperature range (°C): 5.203 - 12.263
  Nitrate (umol/L): 7.162 - 43.209
  Salinity (PPS): 33.368 - 34.397
  Oxygen (ml/l): 0.343 - 5.636
  Phosphate (umol/l): 0.966 - 3.280
  Silicate (umol/l): 9.297 - 95.777

Graphical representation

Depth range (m): 32 - 711

Temperature range (°C): 5.203 - 12.263

Nitrate (umol/L): 7.162 - 43.209

Salinity (PPS): 33.368 - 34.397

Oxygen (ml/l): 0.343 - 5.636

Phosphate (umol/l): 0.966 - 3.280

Silicate (umol/l): 9.297 - 95.777
 
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

Males mature between 54-89 mm ML; size of maturity of females is unknown (Voss et al., 1998). Paralarvae (i.e., pre-photophore stage) have not been described.

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