Gnathia auresmaculosa

The harmfulness of parasites to their host is not always so straightforward, there are often many factors which contribute to the pathology of an infection. The parasite we are looking at today is Gnathia auresmaculosa - a type of blood-sucking crustacean with an interesting life cycle (which you can read about in this post from last year). These little gnathiids are like ticks of the sea, clinging onto passing fish and gorging themselves on blood before dropping off to continue developing. For adult fish, a few gnathiid here and there is probably not a big deal, but for growing juveniles, that is another matter.

Settlement is a critical transitional stage for coral reef fishes, and that is also when they are most vulnerable to parasites like G. auresmaculosa. A recent study by the lab group of Dr. Alexandra Grutter revealed just how costly these ticks of the sea can be to juvenile fishes. Dr. Grutter and her colleagues found that juvenile damselfish which have been fed on by just one of those little blood-suckers exhibit significantly decreased swimming ability, far higher oxygen consumption rate, and are about half as likely to survive than uninfected fishes.

So if you happen to find yourself on a beautiful tropical reef, take a moment to think about all the little baby fishes which are swimming for their lives through the gauntlet of gnathiids - they never mentioned that in Finding Nemo!

Reference:
Grutter, A.S., Crean, A.J., Curtis, L.M., Kuris, A.M., Warner, R.R. and McCormick, M.I. (2011) Indirect effects of an ectoparasite reduce successful establishment of a damselfish at settlement. Functional Ecology 25: 586-594

Columbicola extinctus

Speaking of co-extinctions, here's a contribution that I just got from Anya Gonchar. Columbicola extinctus is a louse that was specific to the Passenger Pigeon, the bird that forever disappeared in the early 20th century. In addition to many advantages of the narrow specialization, C. extinctus has experienced the most drastic of its drawbacks: it has followed its only host into extinction. This could have been one of the impressive examples for a discussion regarding specialist vs. generalist strategies in parasites, if the story hadn't suddenly taken a happy turn. C. extinctus was rediscovered from the Band-tailed Pigeon, while its fellow pseudo-extinct louse C. defectus was suggested to belong to a different species Campanulotes flavus that is still safe and sound. Still, parasite coextinction is documented in numerous other cases where we may not count on such good luck. Fortunately, there is now a large body of literature featuring related topics so that the problem is not neglected. The origin of this blog goes back to celebrating the year 2010 as an International Biodiversity Year. As the previous entries have shown, parasite diversity is enormous indeed. Yet, some parasite species’ existence is challenged. Further reading: Koh L. P. et al. 2004. Species coextinctions and the biodiversity crisis. Science 305, 1632. Dunn R. R. et al. 2009. The sixth mass coextinction: are most endangered species parasites and mutualists? Proc. R. Soc. B, 276, 3037-3045. Clayton D.H., Johnson K.P. 2003. Linking coevolutionary history to ecological process: doves and lice. Evolution, 57(10), 2335–2341. Johnson K.P. et al. 2003. When do parasites fail to speciate in response to host speciation? Syst. Biol. 52(1), 37–47. Johnson K.P. et al. 2009. Competition promotes the evolution of host eneralists in obligate parasites. Proc. R. Soc. B, 276, 3921–3926. Image is of Campanulotes flavus, from the paper: Price et al. 2000. Pigeon lice down under: taxonomy of Australian Campanulotes (Phthiraptera:Philopteridae), with a description of C. durdeni n. sp. Journal of Parasitology 86:948-950.

Ixodes neuquenensis

Today's parasite is a tick described from an endangered marsupial. Ixodes neuquenensis is an ectoparasite of a unique little marsupial known as monito del monte or "mountain monkey" (Dromiciops gliroides).

The "mountain monkey" is the only species still alive from an ancient lineage dating back more than 40 million years. Due to habitat loss, the population of this little marsupial has declined over recent years. This is bad news for I. neuquenensis because it is a very host-specific tick. If the "mountain monkey" goes extinct, it will also spell doom for this tick, along with a whole suite of other parasites and symbionts which are dependent upon this little marsupial.

Reference:
Guglielmone AA, Venzal JM, Amico G, Mangold AJ, Keirans JE (2004) Description of the nymph and larva and redescriptions of the female of Ixodes neuquenensis Ringuelet, 1947 (Acari: Ixodidae), a parasite of the endangered Neotropical marsupial Dromiciops gliroides Thomas (Microbiotheria: Microbiotheriidae). Systematic Parasitology 57:211–219

Nearctopsylla brooksi

Many fleas are quite host specific, although rodent and shrew fleas are occasionally also found on their predators, probably hopping on the nearest warm body when their host is killed. Fleas of the genus Nearctopsylla are primarily found on shrews and moles, but N. brooksi has so far only been reported from weasels (Mustela spp.). It is unlikely to be a weasel parasite so the true host has yet to be discovered. The flea in the photo was found on…you guessed it…a long-tailed weasel.

Contributed by Mike Kinsella.

December 28 - Hyalomma dromedarii

The three wise men are said to have brought three gifts, but perhaps they brought four. The tick, Hyalomma dromedarii, is the most common ectoparasite of camels found in the Middle East. Because of the high temperatures, the females need to burrow down into the sand to lay their eggs. The larvae find a host and feed, but unlike ticks in more temperate climates that usually then drop off to molt, the larvae of H. dromedarii stay put on their host, molt, and feed again. The first host may be a rabbit, hedgehog, bird, or other small livestock, however if the first host that they feed from is a camel itself, they will sometimes stay right there and complete their entire life cycle on the same host. Dropping off into the hot sand is just far too risky, it seems.

Image is from this site.

November 25 - Chelopistes meleagridis

Happy Thanksgiving to all the U.S. readers out there! Seemed appropriate to feature another turkey parasite today (we've had two others recently, i.e. Syngamus trachaea and Trichomonas gallinae ), but this one is something that anyone whose exposure to turkeys is limited to defrosting a Butterball will have no opportunity to come into contact with: the Large Turkey Louse, Chelopistes meleagridis. These lice are very common, especially on wild turkeys and have been introduced to many places via transport of their avian hosts.

November 24 - Lemurpediculus verruculosus

Lemurpediculus verruculosus is a species of louse that infects Microcebus rufus, commonly known as the Eastern Rufous Lemur or the Brown Mouse Lemur. L. verruculosus has a penchant for areas of its host where the skin is thin, the peripheral blood supply is good and where the animal cannot easily groom - thus the ears and, if it is on a male, the testes. This species was originally discovered back in 1951 as part of a collecting expedition by the famous medical entomologist Harry Hoogstraal, but the species description was based only on a single female that had been collected. Recent work on mouse lemurs yielded many more specimens of these lice, allowing the description to be expanded to include males and instar stages as well.

Photo contributed by Lance Durden, one of the authors of the new paper.

November 14 - Pseudolynchia canariensis

Pseudolynchia canariensis is a hippoboscid or louse fly that feeds on pigeons and doves and can transmit the blood parasite Haemoproteus columbae. This species is primarily found in Africa and Asia. If you click on this photo of a P. canariensis fly and look at it carefully, you can see tiny little pink dots near the back of its abdomen. These even smaller things are mites, though in this case they are not really parasitic, but rather phoretic, a phenomenon whereby one kind of organism uses another as a means of transportation. All aboard! This fly is now departing...

November 10 - Holobomolochus confusus

Here’s another ectoparasite of the European flounder, Platichthys flesus (Linnaeus, 1758) (Teleostei: Pleuronectidae). This time, it is Holobomolochus confusus (Stock, 1959) (Copepoda: Bomolochidae). The photo shows an adult female with 2 egg sacs. This specimen was isolated from the fish’s nasal cavity, which is the typical infection site. In comparison with other ectoparasitic copepods of the European flounder, i.e., Acanthochondria cornuta and Lepeophtheirus pectoralis, it is remarkably smaller, occurring less frequently and in lower numbers. This parasite is commonly found infecting the cod, Gadus morhua (Linnaeus, 1758) (Teleostei: Gadidae), and has also been reported from other species of fish.

For details, see the papers below:
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, Universidade do Porto, Faculdade de Ciências, Departamento de Biologia, Rua do Campo Alegre, s/n, FC4, 4169-007 Porto, Portugal.

November 6 - Otodectes cynotis

Many people who have had a dog or a cat as a pet are probably familiar with ear mites - infections that can cause your pet to have brown, cruddy material in their ears, shake their heads, and even itch frantically at their ears. Here's a close-up look at the culprits - Otodectes cynotis. These tiny arachnids are spread from animal to animal via direct contact and then take up residence in the ear canal. The adults lay eggs in the ears and then the mites hatch out and go through a larval stage and two nymphal stage before becoming mature. If left untreated, the mites can induce secondary bacterial or yeast infections, and, in rare severe cases, even deafness in the ear as well.

October 23 - Trombidium holosericeum

The animal in the photo is not a parasite - but its offspring are. Like Eutrombicula alfreduggesi, Trombidium holosericeum is a mite that has parasitic larvae and nymphs. The larvae, commonly known as chiggers, can cause real distress to their hosts - including humans - as they feed. They do not crawl under the skin, nor do they feed on blood - what they do is attach themselves to the skin, pierce it. and inject enzymes that can break down the tissue. A hollow tube known as a stylosome forms - the chiggers will continue to "spit" in these enzymes and then suck up the nutrients. After about 3 to 5 days, they will drop off the host and transform into nymphs. They find a new host, feed in a similar way, and then drop off to molt into adults. The adults are not parasitic, but rather feed on plant juices or are predatory to other small arthropods.

October 22 - Lophoura brevicollum

Lophoura brevicollum is a parasitic copepod that infects the smooth grenadier Nezumia liolepis, a deep sea fish that is found in the bathypelagic depths, about 1200 metres (about three-quarters of a mile) down off the coast of Sinaloa, Mexico. The anterior of the parasite forms an anchor-like holdfast that is embedded in the back of its fish host. One of the more unusual morphological features of this parasite is a pair of peculiar tassels protruding from the abdomen, just in front of its elongated egg sacs. The function of these tassels is possibly related to the habitat of its host. Because L. brevicollum is an ectoparasite, it is exposed to the same environmental conditions as its fish host. In this case, it is the cold, dark surroundings of the deep sea. It has been suggested that the exotic brush-like protrusions of the copepod are adaptations to limited oxygen availability. The protrusions increase the copepod's body surface area to enhance oxygen uptake in the oxygen-poor environment of the bathyal zone.

Reference:
Gomez, S., Deets, G.B., Kalman, J.E., Morales-Serna, F.N. (2010) Lophoura brevicollum n. sp. (Copepoda: Siphonostomatoida: Sphyriidae), a parasite of the smooth grenadier Nezumia liolepis (Gilbert, 1890) (Pisces: Macrouridae) from the Eastern Pacific, and a new record and new host of Lophoura unilobulata Castro R. and Gonzalez. Journal of Crustacean Biology 30(1): 129-140.

Contributed by Tommy Leung.

October 15 - Nerocila acuminata

Nerocila acuminata is a parasitic isopod related to Cymothoa exigua, the infamous "tongue-replacer". While N. acuminata doesn't have the morbid habit of replacing the tongue of its host with itself, that certainly doesn't make it more endearing. This isopod clings onto the skin of its fish host, feeding on blood and tissue. When it detects a potential host, this parasites becomes a fish-seeking missile - it launches itself at the target fish like a guided torpedo, making precise directional and speed adjustments to ensure it lands on its target with claws outstretched . Upon contact, the isopod starts digging in, causing terrible, terrible damage to the skin of its fish. In addition to damaged tissue and blood loss, such aggravated injuries can often lead to secondary infection by bacterial infection. Compared with the "tongue-biter", this parasite is one nasty customer.


Contributed by Tommy Leung and photo by Peter Bryant.

October 14 - Lepeophtheirus pectoralis

Lepeophtheirus pectoralis (Müller, 1776) is a caligid copepod usually found on the body surface of the European flounder, Platichthys flesus (Linnaeus, 1758) (Teleostei: Pleuronectidae). Its relatively large body size makes it easily recognizable to any observer. As any other caligid, the parasite has the ability to move freely over the body surface of its host. Notwithstanding, it is remarkable in presenting a well-defined spatial distribution pattern on the host’s body, with the gravid females accumulating, mainly, in the inner surfaces of the pectoral fins. Indeed, this behavioral feature was in the origin of the species name. The records in the literature suggest that the parasite tends to occur with considerably regularity and high numbers on its host.

For details on the species ecology, see the papers below:
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.
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, Universidade do Porto, Faculdade de Ciências, Departamento de Biologia, Rua do Campo Alegre, s/n, FC4, 4169-007 Porto, Portugal.

October 5 - Petromyzon marinus

The sea lamprey, Petromyzon marinus, is a rather gruesome fish - almost right out of a science fiction movie. Hatched in freshwater rivers, the larvae do not possess these fearsome mouths, but are toothless and live a quiet life, buried in the mud where they simply filter feed. Once they grow to a larger size, however, they metamorphosize into the adult, parasitic form, migrate to the sea, and use their suction-cup shaped mouth to latch onto a fish such as a salmon or other bony fish. There, firmly attached, the razor-like teeth and tongue rasp away at the host's flesh and allow the lamprey to feed on blood and bits of tissue. Host fish often die from the excessive blood loss or infections that ensue in the wounds made by these parasites, which can grow up to three feet in length. Native to the coasts of North America and Europe as well as Lake Champlain, which separates New York from Vermont, the construction of the St. Lawrence Seaway may have allowed these parasites to take up firm residence in the Great Lakes, where they now are considered pests due to their feeding on popular game fish such as lake trout and their disruption of the native ecosystem.

September 29 - Tunga penetrans

Tunga penetrans is a species of flea found in Central and South American and the Caribbean that has a similar life cycle to other fleas, such as Ctenocephalides felis, with one major exception. The females on T. penetrans are not content to hop onto a mammal, drink up some blood and move on - no, instead they move in. Commonly known as chigoe fleas (not to be confused with chiggers, which are larval mites), T. penetrans burrows headfirst into the skin, producing a lesion that is almost always on the foot and is extremely itchy and irritating. The lesion will have a black center, which are the two hindmost legs of the flea and her abdomen. After she feeds on blood from the epidermal capillaries, she will swell up like a little balloon and begin to pump eggs out when her host is walking on sandy soil. In this photo, you can see the familiar head of the flea, but her swollen abdomen has been damaged during the removal from the infected person. A large egg is visible, however.

Image is from the CDC Public Health Image Library.

September 24 - Acanthochondria cornuta

Acanthochondria cornuta (Müller, 1776) is a chondracanthid copepod that infects the European flounder, Platichthys flesus (Linnaeus, 1758) (Teleostei: Pleuronectidae), in different geographic locations, including, the coast of Portugal. It is a site-specific marine ectoparasite that occurs generally with regularity and in high numbers in the branchial chambers of its flatfish host. As in all other species of chondracanthids, the male is dwarf, being usually found attached to the female in the vicinity of the genital region. In other words, he is not found directly attached to the fish host and is called a “hyperparasite”.

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 21 - Apodinium floodi

Most dinoflagellates are photosynthetic plankton that form the basis of many aquatic food webs or mutualist symbionts, sharing and sharing alike with their hosts. Apodinium floodi is an exception. Unlike its photosynthetic cousins, it is an ectoparasite, and its host is the pelagic sea squirt Oikopleura labradoriensis. Sea squirts, despite their sac-like appearance, actually belongs to a group of animals call the urochordates, which are more closely related to vertebrate animals than all other invertebrates. Apodinium floodi uses a structure call a peduncle to attach itself to the tail of the sea squirt, and penetrate the host's notochord to absorb nutrients from its blood.

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.

August 27 - Crataerina pallida

Crataerina pallida or the swift lousefly, is a hippoboscid fly that feeds off the blood of swifts that are found in Europe and Asia. The life cycle of the parasite is synchronized with the life cycle of the birds. In the late summer, the flies produce larvae (not just eggs), that will pupate and basically hang out like that over the winter in the birds' nests. The next spring, when the birds lay a new batch of eggs and the hatchlings are present, the flies will finish their development, feed off the baby birds and their parents, and begin the cycle all over again.

August 15 - Spinturnix americanus

Spinturnix americanus is a species of mite that uses several species of vespertillionid bats as its hosts, including little brown bats (Myotis lucifugus), big brown bats (Eptisecus fuscus) and eastern pipstrelles (Pipistrellus subflavus). These mites are specialists on the wings and tail membranes of their flying hosts and have no interest in venturing into the forest of fur on those mammals.

Photo is by Christopher M. Ritzi and comes from this site.