Geographic Range
Symbion pandora
can be found on the lips of Norwegian lobsters,
Nephrops norvegicus
. They are found at depths of 20-40 meters (66-131 feet) from coastal Norway south
to the coastline of the Mediterranean region.
- Biogeographic Regions
- atlantic ocean
Habitat
Symbion pandora
can be found on the mouth bristles of the Norwegian lobster. It attaches to the lobster
with an adhesive disk located on its posterior end.
Symbion pandora
shares a symbiotic relationship with its host. It recieves easy access to food with
out harming or helping the Norwegian lobster. This is called commensalism.
- Habitat Regions
- saltwater or marine
- Aquatic Biomes
- coastal
Physical Description
Symbion pandora has a bilateral, sack-like body with no coelom. There are three basic life stages:
Asexual Feeding Stage- At this stage S. pandora is neither male nor female. It has a length of 347 um and a width of 113 um. On the posterior end of the sack-like body is a stalk with an adhesive disk, which attaches itself to the host. On the anterior end is a ciliated funnel (mouth) and an anus.
Male- S. pandora has a length of 84 um and a width of 42 um during this stage. It has no mouth or anus, which signifies the absence of a digestive system. It also has two reproductive organs.
Female-
S. pandora
is the same size as the male in this stage. It does, however, have a digestive system
which collapses and reconstitutes itself as larva.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
Symbion pandora
reproduces both sexually and asexually. It reproduces asexually by young budding
off from the asexual feeding stage. The sexual cycle begins only during the molting
season of the Norwegian lobster, its host. The male attaches itself to a feeding stage
that contains a developing female and impregnates her. She escapes from the feeding
stage and attaches herself to the host. The larva develops within the female
S. pandora
She then dies and the larva escapes.
- Key Reproductive Features
- sexual
- asexual
- fertilization
- ovoviviparous
Behavior
Symbion pandora
is a solitary species. Interaction seems to be limited to mating and feeding.
Symbion pandora
is sessile most of its life. There are, however, three brief periods of free swimming
which occur between feeding stages.
Food Habits
Symbion pandora
attaches itself on the lips of Norwegian lobsters, where it then sweeps food particles
into its ciliated, disk-shaped mouth. The digestive system is closely intertwined
with the reproductive cycle. A unique feature of the digestive system of
S. pandora
is that it collapses and becomes larva.
- Foraging Behavior
- filter-feeding
Ecosystem Roles
This species is parasitic on Norweigan lobsters.
- Ecosystem Impact
- parasite
Economic Importance for Humans: Positive
Unknown at this time
Economic Importance for Humans: Negative
Unknown at this time
Conservation Status
Symbion pandora
is not on vulnerable, threatened, or endangered status. In fact, large populations
can be found on a single lobster.
Other Comments
Symbion pandora
was an important discovery for scientists in 1995. While it is not considered unusual
to discover a new species, it is unusual to find a new phylum.
Cycliophora
, its designated phylum, was created because the digestive system and reproductive
cycle are unique to the animal kingdom. There are still many unknowns concerning
S. pandora
. Most information on its life cycle and sexual habits are hypothetical.
Additional Links
Contributors
Crystal Parsons (author), Fresno City College, Carl Johansson (editor), Fresno City College.
- Atlantic Ocean
-
the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- saltwater or marine
-
mainly lives in oceans, seas, or other bodies of salt water.
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- asexual
-
reproduction that is not sexual; that is, reproduction that does not include recombining the genotypes of two parents
- fertilization
-
union of egg and spermatozoan
- ovoviviparous
-
reproduction in which eggs develop within the maternal body without additional nourishment from the parent and hatch within the parent or immediately after laying.
- parasite
-
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
- sessile
-
non-motile; permanently attached at the base.
Attached to substratum and moving little or not at all. Synapomorphy of the Anthozoa
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- filter-feeding
-
a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.
- parasite
-
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
References
Burton, M., R. Burton. 1989. Lobster. Pp. 1463 in Marshall Cavendish International Wildlife Encyclopedia . Long Island, NY: Marshall Cavendish Corporation.
Funch, P., R. Kristensen. 14 December 1995. Cycliophora is a New Phylum with Affinites to Entoprocta and Ectoprocta. Nature , 378: 711-714.
Morris, S. 14 December 1995. A New Phylum From Lobster's lips. Nature , 378: 661.
Olsen, J. 18 December 1995. Microscopic Creature Ranks as Real Misfit. Detroit News .
Walker, D. 1995. "A Lobster's Microscopic Friend, Symbion pandora - a new life form and a new phylum" (On-line). Accessed 01/10/04 at http://www.microscopy-uk.org.uk/mag/articles/pandora.html .