Northern Gribble (Limnoria lignorum)
Limnoria lignorum is a wood-boring isopod. Rathke first described the organism in 1799. It is yellowish and up to 5.6 millimeters in length. The Northern Gribble is extensively distributed in temperate and boreal waters of the Northern Hemisphere.
Morphologically, the microorganism has a prolongated oval-shaped body with the size being about thrice the width. The body has three major regions: the head (cephalon), the thorax (paraeon), and the stomach (pleon). The cephalon is globe-shaped and deepens in the first segment of the paraeon. They have small, round, black eyes. The arthropod also possesses two antennae and a flagellum with four articles. The mandible expands at the apex. It has delicate teeth with six setae. While the thorax consists of seven similar segments with a pair of walking limbs (paraeopods) apiece, the pleon bears five pairs of flattened swimming or respiratory appendages (pleopods). The pleotelson has a pair of uropods, with the exopod being shorter than the endopod. The fifth pleon segment has an anteriorly located mid-dorsal longitudinal carina, which bifurcates posteriorly and lacks tubercles (CABI 2017).
The largest identified gribble measured 5.5 mm in length and 1.4 mm in pleotelsonic width. However, its general size is 0.8-4.0 mm. The smallest oviparous female is 3.0 mm in length and 0.8 mm in pleotelsonic plane. A fertilized egg has a diameter of 0.4 mm (CABI 2017).
The specific origin of the organism is still unclear due to identification difficulties coupled with centuries of transoceanic and interoceanic travel of the species in the hulls of wooden ships.
Being a wood-boring arthropod, its distribution is dictated by the availability of timber structures or drown wood. They prefer to bore into the thin upper layer of wood. As such, they are often found boring into the wood in the intertidal zone (Cowles 2015). The bore is about 1-3 centimeters per year after which they cause remarkable damage. They dig by jerking their head back and forth while turning slowly in the burrow. They often make interconnections between their tunnels. The wood chippings pass through the gut in about eighty minutes. They produce cellulase enzymes that assist in the digestion of cellulose in the wood. However, the exact mechanism of metabolism is unknown (Cowles 2015).
They commonly stay in heterosexual pairs with the females positioning themselves at the head of a tunnel with the male behind (CABI 2017). The females carry about eleven pairs of eggs in their marsupium or pouch between the front legs. The eggs hatch into small adults that start burrowing (Cowles 2015). They start burrowing after being submerged in water for some time. This gives time for other wood-degrading organisms to exert their effects.
Their natural spread is thought to be via active and passive migration. These occur as regular seasonal migrations over a few meters because Limnoria is not a strong swimmer. Mechanical transportation could also occur by drifting of infected wood. Additionally, they could be accidentally transported in the hulls of wooden ships and boats. Though they help in clearing the bottom of some bays, they may destroy wooden constructions. Creosote is used to control their attack on submerged timber.
Despite all this information about Limnoria lignorium, there remains a lot of questions about the organisms. They include:
• Phenomena, patterns, and processes of invasion of the genus,
• Nutrition, migratory, and substance seeking behaviour,
• Sources of wood-degrading enzymes in the organism, and
• The role of wood-degrading bacteria and fungi associated with tunnelling activity of Limnoria.
Therefore, a good research question would be, ‘What is the origin of wood-degrading enzymes in gribble and how do they function?’
Cited References.
1. Invasive Species Compendium. Limnoria lignorium (gribble). 2017 October.
Retrieved from https://www.cabi.org/isc/datasheet/109146
2. Cowls D. Limnoria lignorum, Rathke, 1799. (2015). Retrieved from
https://inverts.wallawalla.edu/Arthropoda/Crustacea/Malacostraca/Eumalacostraca/Peracarida/Isopoda/Flabellifera/Limnoria_lignorum.html
Academic levels
Skills
Paper formats
Urgency types
Assignment types
Prices that are easy on your wallet
Our experts are ready to do an excellent job starting at $14.99 per page
We at GrabMyEssay.com
work according to the General Data Protection Regulation (GDPR), which means you have the control over your personal data. All payment transactions go through a secure online payment system, thus your Billing information is not stored, saved or available to the Company in any way. Additionally, we guarantee confidentiality and anonymity all throughout your cooperation with our Company.