Mastigoteuthis pyrodes Young, 1972

Introduction

M. pyrodes is a very distinctive species and the only species of Mastigoteuthis known off Southern California, U.S.A.

Diagnosis

A mastigoteuthid ...

• with integumental photophores and much larger eyelid photophores.
• with broad funnel locking-apparatus lacking undercut posterior margin and antitragus.
• with large club suckers (ca. 0.3 mm diam.)

Characteristics

1. Tentacles
1. Largest suckers of tentacular club about 0.3 mm in longest diameter.
2. Club suckers slightly elongate with 2-3 large knobs projecting into orifice of sucker from outer ring; few tiny distal teeth on inner ring.
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Figure. Tentacular club and club suckers of M. pyrodes, 102 mm ML, NMNH 727463. Left - Oral view of midregion of club. Right - Oral view of large club sucker. Photographs by R. Young.

Scanning electron micrographs of the suckers can be seen here.

2. Funnel/mantle locking-apparatus
1. Funnel component with strong tragus on anteromedial side of broad oval depression.
2. Funnel component with low antitragus rarely visible on posterior border.
3. Funnel component with posterior border not undercut by the oval depression; posterior tip of mantle component does not overlap posterior base (ie, in profile, the mantle does not have a hook-shape).
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Figure. Funnel/mantle locking-apparatus of M. pyrodes. Left - Frontal view of funnel component, holotype. Drawing from Young (1972). Left-center - Frontal view of funnel component, 102 mm ML, immature female, 28°53'N, 118°12'W, preserved, NMNH 727463.

3. Photophores
1. Integumental photophores present.
2. Large oval photophore present on anteroventral margin of eyelid; may be covered by chromatophores.
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Figure. Lateral view of eyelid photophore, paratype, NMNH, 73 mm ML, 29°19'N, 119°21'W. Note the relative size of the eyelid photophore compared to the integumental photophores. Photograph by R. Young.

Comments

Additional features of the description can be found here.

M. pyrodes has the following unique features:

• Integumental photophores on the ventral side of the fins as well as dorsal.
• Funnel locking-apparatus without a antitragus and without a posterior undercut shelf. Mantle component without a hook-nose shape.
• Eyelid photophore far larger than integumental photophores.
• Dorsal photophores present on head and mantle.

Since the integument is often lost during capture, the form of the funnel locking-apparatus is the most useful character.

M. pyrodes is easily separated from the Pacific integumental-photophore-bearing M. dentata by, in addition to the above features, the many (vs two) series of photophores on arms IV and the size, shape and ornamentation of the club suckers.

Distribution

Type locality: 33°32'N, 118°23'W, off the coast of Southern California, Eastern North Pacific. Distribution: Off Southern California; northern Hawaiian waters (ca somewhere between 23°N-28°N).

References

Young, R. E. 1972. The systematics and areal distribution of pelagic cephalopods from the seas off Southern California. Smithson. Contr. Zool., 97: 1-159.