Fritillaria is a genus of larvacean tunicates belonging to the family Fritillariidae.
Anatomy and behavior
Fritillaria differs from other larvaceans like the well-studied Oikopleura by having an elongated trunk region, divided into three distinct sections.
Only the anterior section, comprising the mouth, pharynx and cerebral ganglion, is covered in oikoplastic epithelium. It features a dorsal projection of epithelium, comprising many cellulose-secreting oikoplasts.
The middle section, connected to the front by the oesophagus, comprises the gut and anus, and connects to the tail. In the larva, it is covered by the epithelium, before the latter retracts to the anterior lobe and differentiates into oikoplasts.
The posterior section houses the gonads, growing inside an extension of the trunk.
The latter two sections are devoid of epidermis, instead replaced by a thin cuticular layer secreted by the epithelium during the larval stage.
House
Like other larvaceans, Fritillaria secretes a house made of mucopolysaccharides and cellulose, helping catch food particles for filter-feeding. However, Fritillaria'''s house does not fully cover the animal, instead only expanding on the anterior side. Also, instead of being discarded when clogged like in other larvacean genera, it is here regularly inflated and deflated, helping cleaning off clogged particles.
Distribution Fritillaria is a widespread genus of larvaceans. Unusually for larvaceans, F. rex has been reported to occur deep into the bathypelagic zone in Monterey Bay.
Species
Fritillaria aberrans Lohmann, 1896 Fritillaria abjornseni Lohmann, 1909 Fritillaria aequatorialis Lohmann, 1896 Fritillaria amphigonadis Hopcroft & Robison, 2005 Fritillaria antarctica Lohmann, 1905 Fritillaria arafoera Tokioka, 1956 Fritillaria borealis Lohmann, 1896 Fritillaria charybdae Lohmann, 1926 Fritillaria drygalskii Lohmann, 1923 Fritillaria fagei Fenaux, 1961 Fritillaria formica Fol, 1872 Fritillaria fraudax Lohmann, 1896 Fritillaria gracilis Lohmann, 1896 Fritillaria haplostoma Fol, 1872 Fritillaria helenae Bückmann, 1924 Fritillaria lucifer Hopcroft & Robison, 2005 Fritillaria megachile Fol, 1872 Fritillaria messanensis Lohmann in Bückmann, 1924 Fritillaria pacifica Tokioka, 1958 Fritillaria pellucida (Busch, 1851) Fritillaria polaris Bernstein, 1934 Fritillaria ragusina Garić & Batistić, 2010 Fritillaria rex Hopcroft & Robison, 2005 Fritillaria tenella Lohmann, 1896 Fritillaria urticans Fol, 1872 Fritillaria venusta'' Lohmann, 1896
References