Overview

Brief Summary

Introduction

Three specimens belonging to two distinct species, from the stomach of the fish Alepisaurus ferox, superficially look like sepiolids but lack several of the most basic features of that family and of the Sepioidea. We place these in a new subfamily but are uncertain how they fit into the phylogeny of the Sepiolidae or Sepiolida. A brief discussion of the relationships of the NewSubFamily is found on the Sepiolidae page.

Diagnosis

Sepiolid-like cephalopods:

  • without lateral funnel adductor muscles.
  • without secondary eyelids.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Comprehensive Description

Characteristics

  1. Arms
    1. Arms without protective membranes or trabeculae.
    2. Large arm suckers globular in shape and with circularis muscle.
    3. Dorsal 6 arms connected by web; web deepest between arms III and IV.

    Figure. Venral view of suckers 3-6, arm III of New Species B, showing globular shape of suckers with small, smooth orifices. Arrow points to circularis muscle (shiny band). Photograph by R. Young.

  2. Tentacles
    1. Tentacular clubs small, with suckers only on distal part of club and in two series.
    2. Tentacular club keel restricted to non-sucker bearing region of club; keel curved inward.
    3. Protective membranes absent.
    4. Tentacular stalks long and very slender.

      Figure. Oral view of the tentacular club of New Species B. Photograph by R. Young.

  3. Buccal connectives
    1. Attachments of ventral buccal connectives could not be determined.
  4. Head
    1. Eyes with corneas.
    2. Eyes without secondary eyelids.
    3. Figure. Side view of the left side of the head of New Species B showing the presence of a cornea and the absence of a secondary eyelid. Head stained with methylene blue stain. Photograph by R. Young.

  5. Funnel
    1. Funnel without lateral funnel adductor muscles.
    2. Funnel without funnel valve (uncertain in species A).

    Figure. Ventral view of the funnel and posterior head of New Species A showing the absence of lateral funned adductor muscles. Photograph by R. Young.

  6. Mantle
    1. Stellate ganglia broadly separated; interstellate connective absent.
    2. Mantle component of the funnel locking-apparatus reaches anterior mantle margin.
    3. Anterior mantle margin does not protrude at points of locking-apparatuses.
    4. Figure. Frontal view of the mantle component of the funnel/mantle locking-aparatus of New Species B, showing that it extends, although barely, to the mantle margin. Photograph by R. Young.

  7. Fins
    1. Fins broadly separated posteriorly.
    2. Fins with anterior and posterior lobes.
    3. Figure. Ventral view of the right fin of New Species A showing anterior and posterior lobes. Part of the anterior lobe is folded under the fin. The edge of a glass slide is seen across the fin. Photograph by R. Young.

  8. Photophores
    1. Photophores absent.
  9. Gladius
    1. Gladius Y-shaped. Gladius extremely thin and delicate. Shell sac appears to be wider than gladius at anterior end.
    2. Figure. Dorsal view of New Species B with a drawing showing the approximate positions of the gladius (blue) and basal pockets (red). The basal pockets are entirely separate from the shell sac. Interpretation from a damaged gladius taken from a single specimen. Illustration by R. Young.

  10. Viscera
    1. Gills apparently without branchial canal*.
    2. Ventral mantle adductor muscle present but very reduced.

      Figure. Ventral view of mantle cavity of New Species A. Arrows point to the ventral median adductor muscle located here at the leading edge of the ventral mantle septum and continuing onto the visceral mass passing to either side of the anus.

Comments

The gills were examined in the larger specimen and a branchial canal could not be detected. However, in such a small gill that is not in perfect condition, a branchial canal, if present would be very hard to detect. therefore, this character needs confirmation.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Distribution

Specimens taken from the stomach of Alepisaurus ferox captured within the EEZ of New Caledonia.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!