Overview

Brief Summary

Introduction

A. astrosticta is a relatively large species in the genus attaining 70mm DML. This species is a component of mesopelagic boundary community in Hawaiian waters (Reid et al., 1991).

Brief diagnosis:

An Abralia (Astrabralia) with ...

  • indistinct longitudinal strips of photophores on mantle and head.

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Comprehensive Description

Characteristics

  1. Tentacles
    1. Clubs with about four hooks on ventral side.
    2. Club manus with two rows of large suckers on dorsal side.

    Figure. Oral view of the tentacular club of A. astrosticta, Hawaiian waters. Drawing from Tsuchiya (2000).

  2. Arms
    1. Right ventral arm of male hectocotylized.
    2. Hectocotylus with two subequal sized off-set flaps.

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

  4. Photophores
    1. Eye photophores
      1. Five large silvery organs subequal in size.

    2. Integumental Photophores
      1. Ventral mantle with scattered arrangement of organs forming very indistinct longitudinal strips.
      2. Ventral head with three indistinct, longitudinal stripes of organs.
      3. Large class of integumental photophores unusually large.
      4. Figure. Ventral view of the head and mantle photophores of A. astrosticta, 48 mm ML, immature female, Hawaiian waters, preserved. Photograph by R. Young.

    3. Terminal Arm Photophores
      1. Arm IV with four large ovoidal photophores at tip and photophores not encased in chromatophores.
      2. Terminal suckers lost on oral side of arms IV opposite photophores in both sexes.

      Figure. Ventral view of an arm IV of A. astrosticta, immature male, Northwest Pacific, showing the large terminal photophores (arrows). Drawing from Tsuchiya and Okutani (1989).

    4. Caudal Photophores
      1. Near mantle apex, a pair of ovoidal photophores buried in tissue.

      Figure. Caudal photophores of A. astrosticta. Left - Side and ventral views of, presumably, a mature squid. Drawings from Tsuchiya and Okutani (1989). Right - Ventral and slightly oblique view of the right caudal photophore (arrow), immature female. Photograph by R. Young.

Comment

The large photophores at the tips of arms IV, which is shared with A. asrolineata, is similar to the arrangement in genus Abraliopsis except that they are somewhat smaller and lack the black chromatophores that completely surround the photophores in Abraliopsis (In Abraliopsis the chromatophores, of course, retract during light emission).

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Distribution

West Pacific
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

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Vertical distribution

A. astrosticta is a member of the mesopelagic boundary community in Hawaiian waters (Reid et al., 1991; Young, 1995). Adult specimens were caught at the bottom in 110 and 180m in Hawaii by gillnet and shrimp trawl. Juveniles were caught between 10 and 130m deep at night near Hawaii by pelagic trawls (Young, 1978).

Based on this sparse data, A. astrosticta is thought to inhabit near-bottom waters during the day at upper mesopelagic depth or shallower (i.e., waters with relatively high light levels) as indicated by the large size of their ventral photophores. At night they move into shallower waters, and presumably, move further off the ocean floor (Young, 199? ****)

Geographical distribution

This species was first described from Hawaiian waters. Distribution of the species includes the Ryukyu Islands (Tsuchiya, 1993), the Philippine Sea (Nesis and Nikitina, 1988), Hawaiian waters (Young, 1978; Burgess, 1992), New Zealand and western North Australia (Riddell, 1985; Lu and Philipps, 1985), and eastern North Australia.

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Physical Description

Type Information

Holotype for Abralia astrosticta Berry, 1909
Catalog Number: USNM 214313
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Sex/Stage: female;
Preparation: Isopropyl Alcohol
Year Collected: 1902
Locality: Oahu Island, Barbers Point Light, N 82 Deg., E 2.2 Min., Hawaii, United States, North Pacific Ocean
Depth (m): 351 to 644
Vessel: Albatross R/V
  • Holotype: Berry, S. 1909. Proc. U.S.N.M. 37: 412-414, figs. 4-6.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology

Source: National Museum of Natural History Image Collection

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Ecology

Habitat

Depth range based on 9 specimens in 1 taxon.
Water temperature and chemistry ranges based on 5 samples.

Environmental ranges
  Depth range (m): 106 - 520
  Temperature range (°C): 8.324 - 9.963
  Nitrate (umol/L): 20.734 - 23.058
  Salinity (PPS): 34.658 - 34.770
  Oxygen (ml/l): 2.969 - 3.042
  Phosphate (umol/l): 1.784 - 1.813
  Silicate (umol/l): 34.108 - 46.665

Graphical representation

Depth range (m): 106 - 520

Temperature range (°C): 8.324 - 9.963

Nitrate (umol/L): 20.734 - 23.058

Salinity (PPS): 34.658 - 34.770

Oxygen (ml/l): 2.969 - 3.042

Phosphate (umol/l): 1.784 - 1.813

Silicate (umol/l): 34.108 - 46.665
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Public Domain

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Life History and Behavior

Life Cycle

Life history

Paralarvae

Paralarva of present species is characterized by:

  • Integumental photophores very large.
  • Caudal photophores barely apparent at 3.2mm ML.

Figure. Ventral and dorsal views of A. astrosticta, Hawaiian waters. Scale bar is 1 mm. Note that the caudal photophores are detectable in both paralarvae. Drawings from Young and Harman (1985

(Young and Harman, 1985)

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