Comb Jelly Report

8/9/2019 Comb Jelly Report

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Connor Marshman Professor Tebbitt Biological Illustration

The Surprising Impact of a Small Jelly:

TheMnemiopsis leidy

In the depths of the Gulf of Mexico, the water is still and a seeming perpetual darkness.

uddenl!, a flash of iridescent light can be seen in the distance. "s the shape draws closer, this

otherworldl! form can be discerned. This sea creature, commonl! referred to as the comb #ell! or

sea walnut, is scientificall! classified as theMnemiopsis leidy $Common names for sea walnut,

%&'() . Mnemiopsis leidy differentiates itself as an organism in se*eral uni+ue wa!s its bod!

structure, its hardiness, its beha*ior, and its in*asi*eness.

The structure of theMnemiopsis leidy is basic !et uni+ue. In fact, theMnemiopsis leidy

has a genus all to its own,Mnemiopsis, and therefore can be identified b! its genus name alone

$-ansson, %&&). TheMnemiopsis leidyis transparent and glows iridescent colors. "s far as the

function of this animal/s bioluminescence, scientists ha*e inferred that it ma! be a lure or a

means of communication. -owe*er, none of these ideas ha*e been pro*en conclusi*el!

$0unning, %&&%). "t its maximum, adult si1e, theMnemiopsisleidycan reach a length of six

centimeters and a width of ten centimeters $Tennessee, '223). Its outer membrane has

characteristic bumps. TheMnemiopsishas no brain or teeth. To mo*e, theMnemiopsisuse

small cilia on their bodies to propel them forward $Mnemiopsis genome pro#ect portal, %&'(). In

order to eat, theMnemiopsisleidyfilter feeds. It has no #aw and obtains food b! pumping water

o*er a mucus membrane that strains small animals and organic materials $Ginn et. al, %&&'). The

Mnemiopsiscan eat 1ooplankton, copepods, crustaceans, and other marine in*ertebrates

$Gesamp, et al., '224). 5eproducti*el!,Mnemiopsis leidyis hermaphroditic ha*ing both male

and female reproducti*e parts. Therefore, this organism can fertili1e itself $Gesamp, '224).


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6ertili1ation occurs externall!. TheMnemiopsisspawns b! releasing roughl! eight thousand eggs

at night. 7nce hatched, theMnemiopsisreaches sexual maturit! within thirteen da!s $8ide!s,

'22(). 7n a genomic le*el, the mitochondria of theMnemiopsis leidyis '& kilobases in length

making it the smallest animal 09" se+uence known to scientists $Maxwell, %&'%).

:*olutionaril!, the Ctenophora famil!, which the Mnemiopsis belongs to, is regarded as being

one of the earliest di*erging animal lineages in the e*olutionar! chain. There is some debate

among the scientific communit! as to whether or not Ctenophora or Porifera $sponges) came first

in the e*olutionar! chain, but it is commonl! agreed that the! both di*erged earl! on at around

the same time $Mnemiopsis leidyi, %&'(). TheMnemiopsisis e*olutionaril! related to #ell!fish;

howe*er, theMnemiopsisdoes not sting and does not ha*e tentacles $Tennessee, '223). The

bod! composition of theMnemiopsis leidyis well suited for tough marine conditions and

exhibits profound durabilit! in its en*ironment.

urprisingl!, despite being such a simple organism, theMnemiopsisleidyis a hard!

animal that can thri*e in *arious marine conditions. 6or instance, this animal can li*e in *er!

cold water temperatures $'.< degrees Celsius to


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to its abilit! to thri*e in different en*ironments. To better understand this creature/s adaptabilit!

in water bodies, scientists look to the beha*ior of these marine animals in order to understand its

ecological ad*antages.

In man! wa!s, theMnemiopsis leidyis a beha*ioral m!ster!. cientists ha*e !et to

determine whether or not theMnemiopsisis a social animal. It has e*en been suggested that the

lights the animal emits could be a means of rudimentar! communication with other members of

the same species $0unning, %&&%). ince the organism can reproduce on its own, ha*ing a sexual

partner is not something theMnemiopsis leidyneeds to search out. TheMnemiopsiscan freel!

mo*e about albeit *er! slowl!. 0ue to the bod! shape and slow speed of this creature, the pre! of

theMnemiopsis leidy is unable to sense its impending danger. TheMnemiopsisabilit! to sneak

up on pre! undetected has garnered the organism the title of being ?h!drod!namicall! in*isible@

$Tucker, %&'%). The silent deadliness of theMnemiopsisis one factor that ma! explain the

species/ domination of marine communities in the Black ea, the Caspian ea, and the

Mediterranean ea.

TheMnemiopsis leidys master! of stealth in addition to its durabilit! in multiple marine

en*ironments contributes to the organism/s in*asi*eness into new bodies of water. In one case,

the in*asion of theMnemiopsisinto the Black ea has caused se*eral marine species to dwindle

in population $Tucker, %&'%). Brought into the sea b! boats that the Mnemiopsis had latched

onto, this organism is now consuming a large portion of the Black ea/s small in*ertebrates.

Conse+uentl!, the ecolog! of the area has been negati*el! impacted, because such in*ertebrates

form the basis of the en*ironment/s food chain. Currentl!, measures are being taken to introduce


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predators in the Black ea that consume theMnemiopsis$Gesamp, '224). In the Mediterranean,

fishers t!picall! regard theMnemiopsis leidyas an in*asi*e pest $Gesamp, '224).

5egardless of whether it is percei*ed as a pest, an e*olutionar! window into the past, or

simpl! a da11ling light show in the a+uatic depths, the Mnemiopsis leidyis far from #ust a

floating mass of gelatin. 5ather, the Mnemiopsis displa!s a thoughtApro*oking design through

its peculiar structure, unusual resilience, m!sterious mannerisms, and surprising in*asi*eness.

There is still much to learn about this transparent filter feeder. The more we understand about

this uni+ue animal, the better we can respond to its profound ecological influence on marine

en*ironments. 0espite being one of the oldest and simplest organisms known to man, the

Mnemiopsishas thri*ed and taken o*er *arious a+uatic communities. TheMnemiopsis leidyis

not to be underestimated; this small #ell! has had a large impact on the oceanic ecos!stem at

large
http://animaldiversity.ummz.umich.edu/accounts/Mnemiopsis_leidyi/#79ab65e0912ae02b1e7c791b56021a95http://animaldiversity.ummz.umich.edu/accounts/Mnemiopsis_leidyi/#79ab65e0912ae02b1e7c791b56021a95


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orks Cited

Common 9ames for ea alnut $Mnemiopsis leid!i). $%&'().Encyclopedia of Life.5etrie*ed

"pril =, %&'(.

0unning, P. $%&&%).Mnemiopsis leidy."nimal 0i*ersit! eb. 5etrie*ed "pril (, %&'( at

httpDDanimaldi*ersit!.umm1.umich.eduDaccountsDD

Gesamp. $'224). Opportunistic settlers and the problem of the Ctenophore Mnemiopsis leidyi

invasion in the Black Sea.International Maritime 7rgani1ation. 5etrie*ed "pril


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Tennessee "+uarium. $'223).Mnemiopsis leidyi. Tennessee "+uarium. 5etrie*edMa! ', %&&' at

httpDDwww.tennis.orgDspecialDcomb.html.

Tucker, "bigail. $eptember %&'%). *o" can a +ellyfish this slo" be so deadly %ts invisible.

mithsonian. 5etrie*ed "pril

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Comb Jelly Report