Geographic Range
Lironeca ovalis
is distributed along the Atlantic and Gulf coasts of the United States, ranging from
Wood Holes, Massachusetts to the Mississippi River.
- Biogeographic Regions
- atlantic ocean
Habitat
Lironeca ovalis
is found in aquatic environments on marine fish along coastal areas, specifically
in the Atlantic coast and Gulf of Mexico. It commonly parasitizes
Pomatomus saltatrix
(bluefish),
Morone saxatilis
(striped bass), and
Birdiella chrysura
(silver perch).
- Habitat Regions
- saltwater or marine
- Aquatic Biomes
- coastal
- Other Habitat Features
- intertidal or littoral
Physical Description
Lironeca ovalis
is generally light brown with black chromatophores throughout life. This parasite
has an ovate body, with an average width of 13 mm and an average length of 21 mm.
The head is as wide as long, usually 3 mm, and has indistinct eyes situated post-laterally
and two pairs of antennae. The first pair of antennae are separated by 1 mm and are
composed of six to seven articles, whereas the second pair have eight to nine articles.
The thorax contains seven segments. The first five are each about 2 mm and the last
two are about 1 1/2 mm. The abdomen is not set in the thorax. It is slightly narrower
than the thorax and has six segments, which gradually decrease in width. The uropoda
are equal in length. The inner branch is larger than the outer one by about one half.
The legs, which are the most pertinent feature for this parasite's lifestyle, have
curved dactyli for grasping on to the fish.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
Development
As a species in the family
Cymothoidae
,
Lironeca ovalis
is likely a protandrous, hermaphroditic gill parasite. Free living planktonic larva
can remain free-swimming for a restricted amount of time without a host, about 1-2
weeks. They may alternate between parasitic and free-living stages during the transition
to functional male stages. Early in life it is a parasitic male within the gill chamber
of the host fish. Later it transforms into a female, which can bear free living young
in the marsupium, while still in the gill chamber. The exact stimulus initiating the
sex change is not clear. It may be the presence of a new male entering the gill chamber.
Due to the varying sizes of females and males, it appears that the male will undergo
the sex change molt when a second male attempts to establish on the same host. Nevertheless,
studies have shown that sex change does happen under neuroendocrine control.
Reproduction
As a species in the family Cymothoidae , Lironeca ovalis is likely a protandrous, hermaphroditic gill parasite. Free living planktonic larva can remain free-swimming for a restricted amount of time without a host, about 1-2 weeks. They may alternate between parasitic and free-living stages during the transition to functional male stages. Early in life it is a parasitic male within the gill chamber of the host fish. Later it transforms into a female, which can bear free living young in the marsupium, while still in the gill chamber. The number of eggs carried in the marsupium varies directly with body length, ranging from 300-600. The hatching eggs are released via the gill chamber and opercular opening of the host.
The exact stimulus initiating the sex change is not clear. It may be the presence
of a new male entering the gill chamber. Due to the varying sizes of females and males,
it appears that the male will undergo the sex change molt when a second male attempts
to establish on the same host. Nevertheless, studies have shown that sex change does
happen under neuroendocrine control.
- Key Reproductive Features
- sequential hermaphrodite
- sexual
- Parental Investment
-
pre-fertilization
- provisioning
Behavior
Free-living
Lironeca ovalis
larvae tend to reside near the shore where such hosts as white perch,
Morone americana
are present. In general,
L. ovalis
, tend to be parasites of younger fish, although the reason for this is unknown.
Studies also show that there is a correlation between the size of the parasite and
the length of the fish. The bigger parasite prefers the host with greater length.
Communication and Perception
Crustaceans
have various sensory resceptors, mainly setae over the body. Photoreceptors are also
generally present.
Food Habits
The parasitic isopod is mainly found within the gill chamber between the operculum
and the gills, where it feeds on tissue. Although inhabiting the gill chamber and
closely associated with the host's blood,
Lironeca ovalis
does not feed on the blood.
- Primary Diet
-
carnivore
- eats body fluids
- Animal Foods
- body fluids
Predation
This species is probably consumed by fish in its free-living stages. Mortality for early stages are high due to not reaching a suitable host.
Ecosystem Roles
Lironeca ovalis commonly parasitizes Pomatomus saltatrix (bluefish), Morone saxatilis (striped bass), and Birdiella chrysura (silver perch).
- Ecosystem Impact
- parasite
Economic Importance for Humans: Positive
There are no known benefits for humans.
Economic Importance for Humans: Negative
Although Lironeca ovalis parasitizes fish which are economically important to humans, there seems to be no negative impact because the damage to these fish is so little.
Conservation Status
Lironeca ovalis seems to be in no immediate danger because its type of hosts are abundant.
Additional Links
Contributors
Renee Sherman Mulcrone (editor).
Janelin Sendow (author), University of Michigan-Ann Arbor, Teresa Friedrich (editor), University of Michigan-Ann Arbor.
- 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.
- intertidal or littoral
-
the area of shoreline influenced mainly by the tides, between the highest and lowest reaches of the tide. An aquatic habitat.
- 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.
- protandrous
-
condition of hermaphroditic animals (and plants) in which the male organs and their products appear before the female organs and their products
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- parasite
-
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- parasite
-
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
- carnivore
-
an animal that mainly eats meat
References
Brusca, R. 1981. A monograph on the Isopoda; Cymothoidae(Crustacea) of the eastern Pacific.. Zoological Journal of Linnean Society , 73: 117-199.
Brusca, R., G. Brusca. 2003. Invertebrates . Sunderland, Massachusetts: Sinauer Associates, Inc..
Kabata, Z. 1984. Diseases of marine animals. Vol 4. Part 1. . Germany: Biologishe Anstalt Helgoland.
Marks, R., F. Juanes, J. Hare. 1996. Occurence and effect of the parasitic isopod, Lironeca ovalis , on young-of-the-year bluefish, Pomatomus saltatrix . Canadian Journal of Fisheries Aquatic Science , 53: 2052-2057.
Menzies, R., D. Frankenberg. 1966. Handbook on the common marine isopod Crustacea of Georgia . Athens, Georgia: University of Georgia Press.
Richardson, H. 1901. Key to the isopods of the Atlantic coast of North America, with descriptions of new and little known species.. Proceedings of United States National Museum , 23: 439-579.
Richardson, H. 1905. Monograph on the isopods of North America. Bulletin of United States National Museum , 54: 727.
Sadzikowski, M., D. Wallace. 1974. The incidence of Lironeca ovalis (Say) (Crustacea, Isopoda) and its Effects on the Growth of White Perch, Morone americana (Gmelin), in the Delaware River near Artificiaal Island. Chesapeake Science , 15: 163-164.
Sandifer, P., J. Kerby. 1983. Early life History and Biology of the common Fish Parasite, Lironeca ovalis . Estuaries , 6: 420-425.