October 29, 2016 in Animals & Insects
The Googly Eyed Stubby Squid is a type of stubby squid — which is a group of cephalopods (order Sepiolida) that are closely related to cuttlefish, and are also known commonly as bobtail squid or dumpling squid — that has a very distinct look to it. The eyes really say it all as far as the name is concerned.
In common with other stubby squid (bobtail squid), the species possesses no cuttlebone, and has a rounder mantle than cuttlefish do. They possess 8 suckered arms, two tentacles, and probably look a fair bit like an octopus to many people. Most species are fairly small, as one can see in the photos and video below.
The Sepiolida cephalopods live mostly in the shallow coastal waters of the Pacific Ocean, portions of the Indian Ocean, and, to a lesser degree, in shallow waters off the west coast of South Africa.
The stubby squid swim in a similar fashion to cuttlefish — using both the fins on their mantles and also jet propulsion. Interestingly, they have symbiotic relationships with bioluminescent bacteria (Aliivibrio fischeri) which reside in a specialized light-emitting organ in the animal’s mantle. These symbiotic bacteria feed on a sugar + amino acid solution provisioned by the squid. In return, they hide the “squid’s silhouette when viewed from below by matching the amount of light hitting the top of the mantle.”
To explain, the stubby squid’s specialized organ “contains filters which may alter the wavelength of luminescence closer to that of downwelling moonlight and starlight; a lens with biochemical similarities to the squid’s eye to diffuse the bacterial luminescence; and a reflector which directs the light ventrally.”
Species of the Sepiolida order are iteroparous, and females are thought to lay several clutches of eggs over their lifespan. Egg-clutch size seems to vary significantly based on species, with some laying as many as 400 eggs per clutch, and some as few as 1. Species lifespan varies somewhat, but a median lifespan of roughly 1-year seems to exist for females.
In contrast to some other types of cephalopods, stubby squid don’t seem to practice parental care — the females seem to simply cover the eggs well with sand and then leave them to their own efforts.
Interestingly, symbiosis with V. fischeri bacteria begins immediately upon hatching, with the bacteria colonizing the species’ specialized organ from the surrounding seawater very quickly. This bacterial colonization of the juvenile light-organ is, importantly, seemingly what triggers the morphological changes in the squid that lead to maturity.
Currently, there are around 70 known species of the order. Current scientific classification looks like this:
Subclass Coleoidea: Squid, Octopus, Cuttlefish
Order Sepiolida: Bobtail Squid (Stubby Squid)