Introduction

The cirrate or finned octopods are deep- sea, gelatinous cephalopods found throughout the world's oceans. The cirrates are a poorly known group with many problems in the taxonomy and little known of the biology and ecology. Many species have been described from single, often badly damaged specimens and the sub-order is in need of revision. The cirrates are generally considered to be separated into three families, the Opisthoteuthidae, the Stauroteuthidae and the Cirroteuthidae.

The Opisthoteuthidae is the most speciose of the three cirrate families and includes the genera Opisthoteuthis and Grimpoteuthis. It can be distinguished from the other families of cirrate by the absence of a secondary web. Octopus of the Opisthoteuthis genera are dorso-ventrally flattened,with small fins and the head not distinctly separated from the body, they are the shallowest of the cirrate genera, typically occupying depths of 800-1500m. The genus Grimpoteuthis includes octopus with a bell-shaped body and medium to large fins. Grimpoteuthis are deep-living, at depths of 1500-6000m.

Stauroteuthidae

The Stauroteuthidae possess a secondary web and a U shaped internal shell vestige. The family includes a single genera, Stauroteuthis. Chunioteuthis is a junior synonym of Stauroteuthis. Stauroteuthis includes two species, S. syrtensis from the North Atlantic & S. gilchristi from the South Atlantic.

Cirroteuthidae

The Cirroteuthidae include three genera, Cirrothauma, Cirroteuthis and Froekenia having a complex web and saddle-shaped shell vestige. Cirrothauma is considered monotypic with Cirrothauma murrayi the only species found throughout the Atlantic basin. It is called the blind octopus beacuse the eyes lack lenses. It grows to large size, with large fins and a distinctive long funnel. Cirroteuthis includes two currently recognised species, though there are probably more. C. muelleri is found in the North Atlantic and North Pacific, maturing at small size (<30 cm Total Length.