Lyre Cranch Squid

Bathothauma lyromma

''Bathothauma lyromma'', the lyre cranch squid, is a highly modified species of glass squid from the family Cranchiidae with a distribution which encompasses most of the world's oceans from the tropics to high latitudes.
Paralarval Lyre Cranch Squid (Bathothauma lyromma), Gulf of Mexico The Lyre Cranch Squid (Bathothauma lyromma) can attain a mantle length up to 10cm as a paralarva – this one is ~ 3cm. Adults will attain a mantle length closer to 20cm. The long eye stalks and widely separated fins are two diagnostic characteristic of this paralarval form.  The species is found around the globe in tropical and subtropical waters – typicall found, from 200—1,200m depth (656 — 3,937 feet). All of this is part of the DEEPEND-RESTORE Project (www.deependconsortium.org). All the work has been done out on the RV Point Sur with an amazing captain and crew. A big thanks to CSA and Gray Lawson for management of the MOCNESS system. My participation is by way of the Center for Conservation & Research, San Antonio Zoo. Bathothauma lyromma,Life in the dark

Appearance

''Bathothauma lyromma'' is an atypical glass squid which has very large paralarva which can reach a mantle length of 100mm and has its eyes mounted on a long stalk possesses and a very long brachial pillar. Both these features are reabsorbed as the paralarva matures into a subadult. As an adult it grows to a mantle length of 200mm. The tentacular club only has suckers while the stalk has two rows of suckers and pads at the base and four rows near the club which form an elongated carpal group. The funnel organ has an inverted V-shaped dorsal pad and has no valve. It has almost no tubercles at the fusion of the funnel and the mantle. The small, paddle shaped fins are widely separated and position sub-terminally. There is a photophore on each eye, an unusual feature in the Cranchiidae, shared only with ''Helicocranchia''.

Distribution

''Bathothauma lyromma'' has an extremely wide oceanic distribution and it occurs in oceans throughout the world in tropical and subtropical regions; in the Atlantic it is known to occur from 35° to 45°N to 35° to 40°S. It is, however, absent from the subtropical waters of the south-eastern Atlantic.

Behavior

The long eye-stalked paralarvae of ''Bathothauma lyromma'' are plantonic and are found in the upper water column from less than 100m in depth down to 300m. As they age they undergo an ontogenetic vertical migration in which the larger individuals move down into the deeper depths of more than 1,500 m. They become sexually mature and mate at the depths.

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Status: Least concern
EX EW CR EN VU NT LC
Taxonomy
KingdomAnimalia
DivisionMollusca
ClassCephalopoda
OrderOegopsida
FamilyCranchiidae
GenusBathothauma
SpeciesB. lyromma