1. Phylum Rotifera

5. Phylum Rotifera 1850 described species
most live in freshwater (100’s / L)
Others live in salt water, soil, water film on moss, plankton
small ( μm) but complex

6. Phylum Rotifera 3 general regions: head, trunk, foot
Corona
Phylum Rotifera
Head
Mastax
Trophi
3 general regions: head, trunk, foot
pedal gland in toes glue rotifer to substrate
ciliary corona for feeding, locomotion
complete digestive tract
mastax = muscular pharynx
trophus = grind food
Trunk
Foot

7. Phylum Rotifera protonephridia smooth and striated muscle tissue
Corona
Phylum Rotifera
Head
Mastax
Trophi
protonephridia
smooth and striated muscle tissue
pseudocoelomate
(good hydrostatic skeleton)
syncytial, cuticle-like epidermis (never molted)
parthenogenic
Trunk
Foot

8. Fig.1. Diversity of morphological adaptation in monogononts to different environments. Planktonic: 1 - Synchaeta, 2 - Polyarthra (fam. Synchaetidae); 3 - Asplanchna (fam. Asplanchnidae); 4 - Hexarthra (fam. Hexarthridae); 5 - Conochilus (fam. Conochilidae); 6, 7 - Keratella (fam. Brachionidae). Psammonic: 8 - Dicranophorus, 9 - Wierzejskiella (fam. Dicranophoridae). Phytophylic: 10 - Trichotria, 11 - Macrochaetus (fam. Trichotriidae). Periphytonic: 12 - Collotheca (fam. Collothecidae); 13 - Floscularia (fam.Flosculariidae). Parasitic: 14 - Claria (fam. Clariaidae); 15 - Balatro (fam. Dicranophoridae).
Fig. 2. Unitypical morphological construction in bdelloids. 1 - Habrotrocha, 2 - Otostephanos, 3 - Ceratotrocha (fam. Habrotrochidae); 4 - Philodina, 5, 6 - Rotaria, 7, 8 - Dissotrocha, 9 - Macrotrachela, 10 - Mniobia (fam.Philodinidae); 10, 11 - Adineta (fam. Adinetidae); 12 - Philidinavus, 13 - Abrochta (fam. Philodinavidae).

9. A rotifer trophus

10. More trophi

11. Types of trophi for different types of foods
Uncinate:
For pre-digested food
Ramate:
Grinding only
Malleate:
for gripping and grinding
Virgate:
piercing and sucking
Forcipate: for gripping
Incudate: seizing

12. Acoelomate: e.g. platyhelminthes
Coelomate: Mollusca to arthropoda, All deuterostoma
Pseudocoelomate: e.g. rotifera, acanthocephala, nematoda

13. Parthenogenesis Amictic females (2n) mitosis Summer cycle
(asexual reproduction)
Ova (2n)
Ova (2n)
Mixis stimuli
- photoperiod, temp
- no food
- overcrowded
mitosis
Amictic females (2n)
Spring (photoperiod, temp)
Mictic females (2n)
Winter:
diapause or
cryptobiosis
Dormant zygote (2n)
meiosis
Ova (1n)
Sperm (1n)
Autumn cycle
(sexual reproduction)
mitosis
Males (1n)

14. P. Acanthocephala: Spiny headed worms

15. P. Acanthozoa: Spiny headed worms
1100 spp, all parasites of vertebrates (esp fish)
Spiny head used for attachment
Lack gut
Larvae parasitize
crustacea, insecta
Pseudocoelomate
Intestine of eider duck with acanthocephalan parasites

16. Acanthor Cystacanth Acanthella
Acanthocephala·Fig. 2. Life cycle of common acanthocephalan species (cf. Table 1). A Macracanthorhynchus hirudinaceus; B . 1 The adults live in the intestine of their final hosts, being attached by their hooked proboscis. The penetration of the intestinal wall leads to inflamed protrusions (IP) appearing along the outer side. 2 After copulation the adult females excrete eggs for several months (patent period). These eggs are passed fully embryonated (i.e. they contain the hooked larva) with the feces of the host. 3-6 Intermediate hosts ( Gammarus spp. or beetle larvae) become infected by ingesting infective eggs. Inside the intestine the acanthor is released from the egg (4; RA), enters the body cavity and is transformed into an larva (5). The latter matures within days (in M. hirudinaceus) and is described as an infective larva (). Infection of the final hosts occurs when they swallow infected intermediate hosts. The young worms reach sexual maturity within days in M. hirudinaceus (after 20 days in Polymorphus minutus) and start egg production (= end of prepatent period). AC, acanthor; BH, body hooks; IP, inflamed protrusion of IW; IW, intestinal wall; PH, proboscis hooks; RA, released acanthor

17. Acanthor Cystacanth Acanthella
Acanthocephala·Fig. 3. Life cycle of two common acanthocephalan species parasitizing fish. A ; B . 1 Adults are attached to the intestinal wall of their final hosts, trouts (A) or chubs and other fish (B). 2 Fully embryonated eggs are passed with host's feces. 3-6 Intermediate hosts (A Asellus aquaticus, B ostracod crustaceans) are infected by uptake of eggs. Inside their intestine the acanthor larva (4) is released from its enters the body cavity and becomes transformed into the acanthella larva (5). This stage differentiates to the infective larva without in about days (6) depending on outer conditions. Final hosts are infected by swallowing intermediate hosts. In A. anguillae a may also become involved. When bleaks and some other fish ingest intermediate hosts (Asellus aquaticus), the infective larva enters the fish viscera, but there is no further development, but quick depeneration. Infected paratenic hosts may be a second source of infection for the final host. Neoechinorhynchus rutili and A. anguillae reach sexual maturity in about or days respectively (prepatent period). Adults live only for about 2-3 months (patent period). AC, acanthor; IP, inflamed protrusion of IW; IW, intestinal wall; LM, PH, proboscis hooks