Phylliroe

Last updated

Phylliroe
Phylliroe bucephalum.jpg
Phylliroe bucephalum
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Order: Nudibranchia
Suborder: Cladobranchia
Family: Phylliroidae
Genus: Phylliroe
Péron & Lesueur, 1810 [1]
Species

Phylliroe is a genus of average sized (up to 5.5 centimetres or 2.2 inches), highly transparent pelagic nudibranchs, marine gastropod molluscs in the order Opisthobranchia, that consists of two known species. [2] It is notable for being an open-ocean hunter that resembles a fish in body plan and locomotion, an example of convergent evolution. [2]

Contents

Distribution and habitat

Ecology

Juveniles of P. bucephalum are found exclusively feeding on the bell of the hydromedusa Zanclea costata (this junior synonym was given precedence over Mnestra parasites). At first the nudibranch is attached to the inside of the bell of the meduse with its very small foot. It sucks tissue from the ring, radial canals and manubrium of the meduse and grows from 1.6 mm to 11 mm in just ten days, while the meduse shrinks. When the slug is as big as the meduse, it starts to swim, eating the remaining parts, including the tentacles. [3]

In adulthood its diet is no longer restricted to Zanclea, although observations of feeding behaviour are sparse. Phylliroe uses its rhinophores (long horns) to prey on jellies, and the nearly vestigial remnant of its foot to adhere to the jelly prey. [2] Phylliroe has been seen approaching a swarm of the larvacean Oikopleura albicans from below, grabbing a specimen with its paired denticulate jaws and swallowing it in half a minute. Adults have also been observed to prey on the meduse Aequoria. [3]

Branches of the digestive tract may contain symbiontic zooxanthellae, but this relationship has not yet been studied. It is unclear if all specimens of P. bucephalum harbor these symbionts. It is possible they are obtained from their prey. [3]

P. bucephalum sometimes suffers from parasitic trematodes, both attached to its skin and inside its body. [3]

Related Research Articles

<span class="mw-page-title-main">Nudibranch</span> Order of gastropods

Nudibranchs are a group of soft-bodied marine gastropod molluscs that shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown", "marigold", "splendid", "dancer", "dragon", and "sea rabbit". Currently, about 3,000 valid species of nudibranchs are known.

<span class="mw-page-title-main">Sea angel</span> Clade of gastropods

Sea angels are a large group of small free-swimming sea slugs, not to be confused with Cnidarians, classified into six different families. They are pelagic opisthobranchs in the clade Gymnosomata within the larger mollusc clade Heterobranchia. Sea angels were previously referred to as a type of pteropod.

<span class="mw-page-title-main">Sea slug</span> Group of marine invertebrates with varying levels of resemblance to terrestrial slugs

Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails that over evolutionary time have either completely lost their shells, or have seemingly lost their shells due to having a greatly reduced or internal shell. The name "sea slug" is most often applied to nudibranchs, as well as to a paraphyletic set of other marine gastropods without obvious shells.Cucumber

<i>Ocythoe tuberculata</i> Species of cephalopods

Ocythoe tuberculata, also known as the tuberculate pelagic octopus or football octopus, is a pelagic octopus. It is the only known species in the family Ocythoidae.

The Notobranchaeidae, or "naked sea butterflies", are a taxonomic family of floating sea slugs, specifically under the subclass Opistobranchia, also called "sea angels".

<i>Aequorea victoria</i> Species of hydrozoan

Aequorea victoria, also sometimes called the crystal jelly, is a bioluminescent hydrozoan jellyfish, or hydromedusa, that is found off the west coast of North America.

<i>Velella</i> Species of cnidarian

Velella is a monospecific genus of hydrozoa in the Porpitidae family. Its only known species is Velella velella, a cosmopolitan free-floating hydrozoan that lives on the surface of the open ocean. It is commonly known by the names sea raft, by-the-wind sailor, purple sail, little sail, or simply Velella.

<i>Glaucus atlanticus</i> Species of mollusc

Glaucus atlanticus is a species of small, blue sea slug, a pelagic (open-ocean) aeolid nudibranch, a shell-less gastropod mollusk in the family Glaucidae.

<span class="mw-page-title-main">Pelagic thresher</span> Species of shark

The pelagic thresher is a species of thresher shark, family Alopiidae; this group of sharks is characterized by the greatly elongated upper lobes of their caudal fins. The pelagic thresher occurs in the tropical and subtropical waters of the Indian and Pacific Oceans, usually far from shore, but occasionally entering coastal habitats. It is often confused with the common thresher, even in professional publications, but can be distinguished by the dark, rather than white, color over the bases of its pectoral fins. The smallest of the three thresher species, the pelagic thresher typically measures 3 m (10 ft) long.

<span class="mw-page-title-main">Phylliroidae</span> Family of gastropods

The Phylliroidae are a family of nudibranch sea snails, highly adapted to a pelagic lifestyle and occurring in tropical surface waters around the globe. The two species of the genus Phylliroe and Cephalopyge trematoides that have been assigned to this family are small to average in size, slender and highly transparent. They swim by undulating their whole body. Their foot is very small, which helps to reduce drag. They are carnivores that prey on planktonic jelly fish.

<i>Phylliroe bucephala</i> Species of gastropod

Phylliroe bucephala is a parasitic species of pelagic nudibranch, a marine gastropod mollusc in the family Phylliroidae.

<i>Chromodoris magnifica</i> Species of gastropod

Chromodoris magnifica is a sea slug, a species of nudibranch, a shell-less marine gastropod mollusc in the family Chromodorididae. It is the type species of the genus Chromodoris.

<i>Hypselodoris tryoni</i> Species of gastropod

Hypselodoris tryoni is a species of sea slug, a druid nudibranch, a marine gastropod mollusk in the genus Chromodorididae.

<i>Ceratosoma amoenum</i> Species of gastropod

Ceratosoma amoenum, or the clown nudibranch, is a species of colorful dorid nudibranch, a sea slug, a shell-less marine gastropod mollusk in the family Chromodorididae.

<i>Pteraeolidia ianthina</i> Species of gastropod

Pteraeolidia ianthina is a sea slug, an aeolid nudibranch in the family Facelinidae. It is known as a blue dragon, a name it shares with Glaucus atlanticus and Glaucus marginatus.

<i>Chromodoris orientalis</i> Species of gastropod

Chromodoris orientalis is a species of colourful sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae. Sea slugs are generally very beautifully colored organisms with intense patterns and ranging in sizes. The Chromodoris orientalis specifically is a white sea slug with black spots in no particular pattern with a yellow, orange, or brown in color ring around its whole body and on its gills. There is much discussion on where it is found, what it eats, how it defends itself without a shell, and its reproduction methods. This is all sought after information because there is not much known about these animals.

<i>Scyllaea pelagica</i> Species of gastropod

Scyllaea pelagica, common name the sargassum nudibranch, is a species of nudibranch, a marine gastropod mollusc in the family Scyllaeidae. This species lives among floating seaweed in the world's oceans, feeding on hydroids.

Cephalopyge trematoides is a pelagic species of nudibranch. A free-swimming marine gastropod in the family Phylliroidae. Cephalopyge trematoides is the only known species in its genus.

<i>Okenia zoobotryon</i> Species of gastropod

Okenia zoobotryon is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae. It is normally found on the colonial bryozoan Amathia verticillata on which it lives and feeds.

<i>Phyllodesmium poindimiei</i> Species of gastropod

Phyllodesmium poindimiei is an Alcyonacea feeding, aeolid nudibranch Gastropod belonging to the family Facelinidae. Cerata are important in this clade in terms of their physical defense and efficient metabolic processes. This species is spread sporadically along tropical coastal regions such as Australia, Hawaii, and the Indo-Pacific living in diverse marine habitats such as coral reefs. Unlike other species in the Opisthobranch Mollusca clade, P. poindimiei’s lush pink cerata are used for defensive purposes other than Nematocyst (dinoflagellate) capture and toxin release. Organismal ties within these thriving, tropical ecosystems can be determinants of environment change, which affects massive coral ecosystems. Continuously changing marine ecosystems, such as coral reefs, are directly linked to the evolution of organisms that live and thrive in the tropics such as the soft nudibrach P. poindimiei.

References

  1. Péron & Lesueur C. A. (1810). "Histoire de la famille des Mollusques Ptéropodes. Caractères des dix genres qui doivent la composer". Annales du Muséum National d'Histoire Naturelle15: 57-69, page 65, plate 1, fig. 1-3.
  2. 1 2 3 Helm, R.R. (2015-11-18). "Meet Phylliroe: the sea slug that looks and swims like a fish". Deep Sea News. Retrieved 22 November 2015.
  3. 1 2 3 4 5 Lalli, Carol M.; Gilmer, Ronald W. (1989). Pelagic Snails: The Biology of Holoplanktonic Gastropod Mollusks. Stanford University Press. ISBN   9780804714907.

Further reading