Contributed by Tommy Leung.
"So, naturalists observe, a flea has smaller fleas that on him prey; and these have smaller still to bite ’em; and so proceed ad infinitum."
- Jonathan Swift
September 30, 2010
September 30 - Aggregata octopiana
Contributed by Tommy Leung.
September 29, 2010
September 29 - Tunga penetrans

Image is from the CDC Public Health Image Library.
September 28, 2010
September 28 - Aphanomyces invadans
Reference:
Kiryu et al. (2003) Infectivity and pathogenicity of the oomycete Aphanomyces invadans in Atlantic menhaden Brevoortia tryannus. Diseases of Aquatic Organisms 54: 135-146.
(Photo from this paper.)
Contributed by Tommy Leung.
September 27, 2010
September 27 - Odhnerium sp.

Digeneans are flatworms famous for their plastic morphology, that is, the flexibility expressed in their body plan; the variations-on-a-theme, if you will. There are few better examples than Odhnerium species, a genus of accacoeliid worms parasitic in the intestine of the ocean sunfish, Mola mola. Most digeneans have either 0, 1 or 2 suckers, with 2 being the overwhelmingly most common body plan: an oral and a ventral sucker. Then along comes Odhnerium, which lines the anterior dorsal surface with muscular pseudosuckers, in this case at least 9 (they show up as blue waves). What’s a pseudosucker? Good question! It turns out that suckers have a very specific definition: a capsule-bound muscular attachment organ that works by suction. In this case, the suckers are apparently not capsule-bound (i.e. there’s no connective tissue membrane around them) so they only look like suckers – hence “pseudosuckers”. Still, it’s a pretty crazy departure from the normal body plan for digeneans, and it’s hard not to wonder what they’re so important for, since tens of thousands of gut dwelling fluke species do just fine without them. And while we’re at it, check out the ventral sucker, which is up on a sort of stalk called a pedicel, and is more like a pair of muscular flaps forming a clamp, than a typical round sucker.
The blue appearance of the suckers in this particular photo is a trick of the light. The photo was taken during processing to make the specimen into a permanent wholemount. There’s a step in the process when the worm has had all its water replaced by ethanol, and then you gradually replace the ethanol with a clearing agent like eugenol or (in this case) methyl salicylate. As the met-sal penetrated and cleared the tissues, this handsome colour was created for a few seconds, and I snapped the pics because it looked cool.
Contributed by Al Dove.
September 26, 2010
September 26 - Carnus hemapterus
September 25, 2010
September 25 - Isospora felis

Image by Steve Upton.
September 24, 2010
September 24 - Acanthochondria cornuta

See these papers:
1. Cavaleiro, F. I. & Santos, M. J. (2007) Survey of the metazoan ectoparasites of the European flounder Platichthys flesus (Linnaeus, 1758) along the north-central Portuguese coast. Journal of Parasitology 93, 1218-1222.
2. Cavaleiro, F. I. & Santos, M. J. (2009) Seasonality of metazoan ectoparasites in marine European flounder Platichthys flesus (Teleostei: Pleuronectidae). Parasitology 136, 855-865.
Contributed by Francisca I. Cavaleiro & Maria J. Santos.
September 23, 2010
September 23 - Diphyllobothrium latum

Image from the CDC Public Health Image Library.
Read more about this parasite in Robert Desowitz's wonderful book, "New Guinea Tapeworms and Jewish Grandmothers".
September 22, 2010
September 22 - Ambylomma americanum

September 21, 2010
September 21 - Apodinium floodi

It is an evolutionary marvel - a single-celled algae which has evolved to make a living by sucking blood from a pelagic animal!
Contributed by Tommy Leung.
September 20, 2010
September 20 - Neospora caninum

Photo of N. caninum in calf brain by Steve Upton.
September 19, 2010
September 19 - Phasmarhabditis hermaphrodita

Image is from this site.
September 18, 2010
September 18 - Coitocaecum parvum
Coitocaecum parvum is a trematode found in New Zealand. Like most trematodes, it has a three host life-cycle, with amphipods (a kind of small crustacean) serving as a second intermediate host. Usually, in order for the parasite to complete its life-cycle and reach sexual maturity, the amphipod host needs to be eaten by the parasite's definitive host, a small freshwater fish call the common bully (Gobiomorphus cotidianus). However, in situations where the fish is absent, the parasite has another trick up its sleev...err, ventral sucker... Instead of waiting for a fish to come along (which might not happen before its short-lived crustacean host dies), it switches up its game - it becomes "progenetic" and reach sexual maturity within the amphipod itself. Because it is a hermaphrodite, it can simply fertilise its own eggs, which will be released into the environment when the amphipod dies and decompose.
The photo shows a pair of progenetic C. parvum (one still in its cyst, the other released from its cyst and surrounded by its own eggs) next to a pair of non-progenetic C. parvum.
Reference:
Lagrue, C., and R. Poulin. 2007. Life cycle abbreviation in the trematode Coitocaecum parvum: can parasites adjust to variable conditions? Journal of Evolutionary Biology 20: 1189-1195.
Contributed by Tommy Leung.
September 17, 2010
September 17 - Travassostrongylus sp.

Contributed by Phil Scheibel.
September 16, 2010
September 16 - Balaenophilus manatorum

September 15, 2010
September 15 - Entamoeba histolytica
September 14, 2010
September 14 - Cystobranchus virginicus

Contributed by Jessica Light.
See this paper for more info.
September 13, 2010
September 13 - Paucivitellosus fragilis
Photo came from:
Abdul-Salam, J. and Sreelatha, B.N.S. (1996) Light and scanning electron microscopic observations of the rediae and cercariae of Paucivitellosus fragilis (Digenea, Bivesiculidae). Acta Parasitologica 41:108-114.
Contributed by Tommy Leung.
September 12, 2010
September 12 - Clonorchis sinensis

September 11, 2010
September 11 - Crocodylocapillaria longiovata

September 10, 2010
September 10 - Agema silvaepalustris
Today's parasite is Agema silvaepalustris and it is found in the lungs of the dwarf crocodile Osteolaemus tetraspis, which lives in the equatorial rain forest zone of West and Central Africa. The crocodiles become infected when they eat fish that possess the larval instars of A. silvaepalustris. The lungs of an individual crocodile can be infected with a few dozen to over a hundred of these parasites, and it is amazing to think that these weird little banana-shaped critters are more closely related to shrimps and crabs than any actual "worm"!
For further details, see:
Riley, J., Hill G. F., Huchzermeyer, F. W. (1997) A description of Agema, a new monotypic pentastomid genus from the lungs of the African dwarf and slender-snouted crocodiles. Systematic Parasitology 37: 207-217.
Contributed by Tommy Leung.
September 9, 2010
September 9 - Trichinella zimbabwensis
For more details, see:
Pozio, E. et al. (2002) Trichinella zimbabwensis n.sp. (Nematoda), a new non-encapsulated species from crocodiles (Crocodylus niloticus) in Zimbabwe also infecting mammals. International Journal for Parasitology 32:1787-1799.
Contributed by Tommy Leung.
September 8, 2010
September 8 - Eimeria alligator

September 7, 2010
September 7 - Acanthostomum americanum
Image adapted from:
Moravec, F. 2001. Some helminth parasites from Morelet's crocodile, Crocodylus moreletii, from Yucatan, Mexico. Folia Parasitologica 48: 47-62.
Contributed by Tommy Leung.
September 6, 2010
September 6 -Haemogregarina crocodilinorum

September 5, 2010
September 5 - Griphobilharzia amoena
Description for Griphobilharzia amoena:
Platt, T. R., Blair, D., Purdie, J. and Melville, L. (1991) Journal of Parasitology 77:65-68.
The paper which suggest crocodiles reevolved ectothermy:
Seymour, R. S., Bennett-Stamper, C. L., Johnston, S. D., Carrier, D. R. and Grigg, G. C. (2004) Physiological and Biochemical Zoology 77:1051-1067.
Contributed by Tommy Leung.
September 4, 2010
September 4 -Corynosoma enhydri
Contributed by Mike Kinsella.
September 3, 2010
September 3 - Liriopsis pygmaea

Liriopsis pygmaea attaches itself to the externa of B. callosus and parasitises it (see pale blobs in photo, arrow indicating externa of B. callosus). L. pygmaea belongs to the group of isopods call the cryptoniscid. While most people are familiar with isopods in the form of slaters and pillbugs you see in the garden, adult L. pygmaea bears a closer resemblance to the cherry tomatoes which might be growing in the said garden than their isopod cousins. Just as B. callosus castrate its crab host, L. pygmaea does the same to the rhizocephalan - drawing resources away from the parasitic barnacle and using it for its own reproduction. So in this case, the castrator, becomes the castrated.
The photo and the info for write up came from this paper:
Lovrich, G. A., Roccatagliata, D., Peresan, L. (2004) Hyperparasitism of the cryptoniscid isopod Liriopsis pygmaea on the lithodid Paralomis granulosa from the Beagle Channel, Argentina. Diseases of Aquatic Organisms 58:71-77.
Contributed by Tommy Leung.
September 2, 2010
September 2 - Bdellovibrio bacteriovorus

September 1, 2010
September 1 - Dactylanthus taylorii

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