Loricifera
-
Upload
jorgeatte-eleanor-rostata -
Category
Documents
-
view
38 -
download
2
description
Transcript of Loricifera
PHYLUM LORICIFERA
Christen Jene CorilloLora Mae Garcia
Undescribed species of Spinoloricus
(Loricifera; stained with Rose Bengal).
PHYLUM LORICIFERA
“loricus”- corset, girdle
“ferro” – carry, bear
“girdle bearers” about 100 species discovered microscopic (>0.5 mm) marine
- from shallow to deep water
- between particles of sediment multicellular
Characteristics:
• Bilateral, unsegmented, and probably pseudocoelomate
• Body divided into a head, neck, and thorax, all retractable into an abdomen
• Abdomen housed in cuticular lorica• Mouth is located at the end of oral cone
beset with stylets• Gut complete
• No circulatory or respiratory organs• Nervous system present• One pair of protonephridia• Gonochoristic; development includes
unique Higgins-larva• All inhabit marine, interstitial
environments, first found in clean shell-gravel sediments
Defining Characteristic
• spinelike, chitinous scales (scalids) on the introvert are operated by individual muscles
• set of spiny plates called a lorica around their abdomens
• spiny head• head, neck, and thorax retract, like a
telescope, into the lorica
ANAT
OM
Y
EXTE
RNAL
INTE
RNAL
Three body regions:
1. head
- mouth, oral stylet
- rings of scalids
2. neck
3. trunk
- lorica/corselet
Larvae
- caudal feet
Brain Ganglion Stomach Esophagus
Ventral view of adult female loriciferan (Nanaloricus mysticus)
Nanaloricidae
Pliciloricidae
Nanaloricus
PliciloricusRugiloricus
ArmorloricusPheniciloricusSpinoloricus (2007)Australoricus (2009)
Nanaloricus mysticus
Higgins larva
mouth cone
scalids
neck
lorica
sensory hairs swimming
appendage
anus
Nanaloricus mysticus
Adult
scalids
mouth
styletsintrovert
neck
anus
lorica
Nanaloricus mysticus
LOCOMOTION
ADULT crawl using their scales and mouth cone
LARVAE use spines and bristles to crawl swim using toes
FOOD CAPTURE and DIGESTIONectoparasites or predators (?)
stylets for piercing and sucking up body fluids of plants and animals
through gut
NERVOUS SYSTEM
well developed brain
nerves
ganglion
REPRODUCTION and DEVELOPMENT separate sexes some are parthenogenetic internal fertilization oviparousshedding and resting stages Higgins larva
- specialized immature form
- pair of oarlike scales called toe for locomotion neoteny
The life history of Rugiloricus. The egg (A); the developing embryo in the egg (B); First instar larva (C); Last instar larva with mature ovary which develops by parthenogenesis and neoteny (D); Cyst larval form with developing larvae inside (E); A neotenous larva (F); Post larva (G); Adult female with ovaries (H1); Adult male with testes (H2).
Life Cycle of Loriciferans
Thank You for listening…
God bless