Profilicollis

Profilicollis
Profilicollis altmani
Scientific classification
Kingdom:	Animalia
Phylum:	Acanthocephala
Class:	Palaeacanthocephala
Order:	Polymorphida
Family:	Polymorphidae
Genus:	Profilicollis Meyer, 1931
Species
see text

Profilicollis is a genus of acanthocephalan parasites of crustaceans. The status of the genus Profilicollis has been debated, and species placed in this genus were formerly included in the genus Polymorphus. However, research on the morphology of the group and their use of hosts has concluded that Profilicollis and Polymorphus should be regarded as distinct genera, and species previously described as Polymorphus altmani are now referred to as Profilicollis altmani in the literature.^[1] Profilicollis parasites infect decapod crustaceans, usually shore crabs, as intermediate hosts, and use many species of shorebirds as definitive hosts.

Life cycle

Profilicollis altmani is a species of acanthocephalan parasite, also described as Profilicollis kenti and Profilicollis texensis, although the status of this parasite is not fully resolved.^[2][3] This parasite first develops in the haemocoel of Emerita spp. mole crabs, in North and South America. After infection of the mole crab (the intermediate host), the parasite becomes a dormant cystacanth until the crab is eaten by a suitable bird, such as the surf scoter Melanitta perspicillata or herring gull, Larus argentatus (the final or definitive host). Once the parasite cystacanth has passed through the stomach of the bird, it develops into the adult worm and attaches to the intestines of the bird. Eggs produced by the parasite are released from the bird with bird feces and enter the ocean. Here the eggs are transported by the currents until they are accidentally ingested by a filter-feeding mole crab. Interestingly, Profilicollis altmani has become the subject of increasing research as it has been discovered that this parasite is contributing to a substantial proportion of the deaths of the southern sea otter, Enhydra lutris nereis. Between 1998 and 2001, between 13% and 16.2% of sea otter carcasses found around central California the cause of death was determined to be a direct result of acanthocephalan peritonitis, caused by this species of parasite. Several decades ago, the proportion of sea otters dying because of these parasites was almost negligible. Most of the sea otters that were found to be killed by infections by Profilicollis altmani were either young juvenile or older female otters, and it is hypothesized that they feed on sand crabs because they are less skilled at foraging or because of a decrease in their preferred prey.^[4][5]

Species and hosts

• Profilicollis altmani – infects mole crabs as intermediate hosts in the United States. Final hosts include scoters, Melanitta spp.; gulls, Larus spp.; lesser scaup, Marilla affnis; sanderling, Calidris alba; dunlin, Calidris alpina; whimbrel, Phaeopus hudsonicus; rhinoceros auklet, Cerorhinca monocerata; and willet, Catoptrophorus semipalmatus.^[6]
• Profilicollis antarcticus – infects shore crabs such as Hemigrapsus crenulatus and gulls such as Larus dominicanus in Chile and New Zealand.^[7]
• Profilicollis botulus – infects shore crabs such as Hemigrapsus oregonensis and the invasive green crab Carcinus maenas as well as the lobster Homarus americanus. Its final hosts are shorebirds such as common goldeneye, Bucephala clangula; Barrow's goldeneye, B. islandica; greater scaup, Aythya marila; eider duck, Somateria mollissima; and long-tailed duck, Clangula hyemalis.^[8]
• Profilicollis bullocki – infects mole crabs as intermediate hosts in Chile and Peru. Final hosts include gulls, including Larus belcheri, L. dominicanus and L. pipixcan.^[9]
• Profilicollis chasmagnathi – infects estuarine crabs (described in Uruguay) and gulls, including Larus atlanticus.^[10]
• Profilicollis formosus – infects Macrobrachium and domestic ducks in Taiwan.^[3][11]
• Profilicollis major – infects the Atlantic rock crab Cancer irroratus, although likely other species as well. This parasite has also found in the intestines of sea otters, although it appears to be much less pathogenic to the otters than Profilicollis altmani.^[4]
• Profilicollis novaezelandensis – infects shore crabs such as Hemigrapsus crenulatus, and mud crabs Macrophthalmus hirtipes and Helice crassa. They then infect birds such as the South Island pied oystercatcher Haematopus ostralegus finschi and bar-tailed godwit Limosa lapponica in New Zealand.^[7]
• Profilicollis sphaerocephalus – infects many grapsid crabs (including Brachynotus spinosus, Cyclograpsus granulosus, Paragrapsus gaimardii, Paragrapsus laevis and Paragrapsus quadridentatus) 1 species of portunid crab (Nectocarcinus integrifrons). This species also infects gulls.^[12]

Behavioral manipulation

Like many other acanthocephalans, recent studies have shown that the presence of cystacanth of Profilicollis antarcticus causes behavioral alterations due to changes in the levels of hemolymph dopamine in its intermediate host, the crab Hemigrapsus crenulatus. These changes in the biogenic amino levels can cause behavioral changes such as changes in response to external stimuli resulting from neurological damages (escape behavior), increased conspicuity resulting from modified pigmentation and/ or behavior and castration. Previous studies have also shown that crabs infected with cystacanths exhibit higher metabolic rates and activity levels than non-parasitized crabs.

The free living conditions of cystacanths in the hemocoelomic cavity of the intermediate host maybe interpreted as the direct way of altering the dopamine metabolic pathway.The alteration of dopamine levels in the hemolymph system implies that there is a generalized effect of the parasite on the body of its intermediate host, rather than an effect on the nerve ganglion level. Therefore, the increase in activity and metabolic rates for this host parasite system could be a consequence of higher metabolic cost of maintenance for the host, linked to the synthesis of monoamines and/ or the physiological consequences of their bio-availability. This altered physiological condition is beneficial for the parasite,considering that their final goal is to increase transmission by increasing the probability of predation on the intermediate host(the crab)by its definitive host(the gull).^[13]

Species

• Profilicollis altmani (Perry, 1942)
• Profilicollis arcticus (Van Cleave, 1920)
• Profilicollis antarcticus (Zdzitowiecki, 1985)
• Profilicollis botulus (Van Cleave, 1916)
• Profilicollis bullocki (Mateo, 1982)
• Profilicollis chasmagnathi (Holcman-Spector, Mane-Garzon and Dei-Cas, 1977)
• Profilicollis formosus Schmidt and Kuntz, 1967
• Profilicollis kenti Van Cleave, 1947
• Profilicollis major Lundström, 1942
• Profilicollis minutus (Goeze, 1782)
• Profilicollis novaezelandensis (Brockerhoff, 2002)
• Profilicollis sphaerocephalus (Bremser, 1819)
• Profilicollis texensis Webster, 1948

References

Wikispecies has information related to: Profilicollis