''Haplometra cylindracea'' is a

trematode Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host ...

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

frogs A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

. Adult worms measure usually 10 mm and they are located in the lungs. ''H. cylindracea'' develops through 2 intermediate hosts: the first, a freshwater snail, the second, a water beetle.

Morphology

Adult worms are usually 10 mm long and they have elongate, cylindrical body. Ventral sucker is smaller than oral sucker. Eggs are dark brown in colour and measures 220 µm.

Cercariae Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secr ...

contains characteristic stylet.

Hosts

Definitive hosts are frogs. ''H. cylindracea'' was documented in ''

Rana temporaria The common frog or grass frog (''Rana temporaria''), also known as the European common frog, European common brown frog, European grass frog, European Holarctic true frog, European pond frog or European brown frog, is a semi-aquatic amphibian ...

'', ''

Rana esculenta The edible frog (''Pelophylax'' kl. ''esculentus'') is a species of common European frog, also known as the common water frog or green frog (however, this latter term is also used for the North American species ''Rana clamitans''). It is used ...

'', ''

Rana ridibunda The marsh frog (''Pelophylax ridibundus'') is a species of water frog native to Europe and parts of western Asia. Description The marsh frog is the largest type of frog in most of its range, with males growing to a size around 100 mm (3.9 ...

'', '' Rana dalmatina'', ''

Rana arvalis The moor frog (''Rana arvalis'') is a slim, reddish-brown, semiaquatic amphibian native to Europe and Asia. Moor frogs are known for their ability to freeze solid and survive thawing. The frog makes use of various cryoprotectants i.e. antifreeze ...

'', ''

Bufo ''Bufo'' is a genus of true toads in the amphibian family Bufonidae. As traditionally defined, it was a wastebasket genus containing a large number of toads from much of the world, but following taxonomic reviews most of these have been moved to ...

'' spp., ''

Bombina fire-bellied toads are a group of six species of small frogs (most species typically no longer than ) belonging to the genus ''Bombina''. The name "fire-bellied" is derived from the brightly colored red- or yellow-and-black patterns on the toa ...

'' spp. First intermediate host is snail from family

Lymnaeidae Lymnaeidae, common name the pond snails, is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila. Lymnaeidae is the only family within the superfamily ...

, i.e. ''

Galba truncatula ''Galba truncatula'' is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.Neubauer, Thomas A. (2014). Galba (Galba) truncatula (Müller, 1774). Accessed through: World R ...

'', '' Lymnaea palustris'', ''

Radix In a positional numeral system, the radix or base is the number of unique digits, including the digit zero, used to represent numbers. For example, for the decimal/denary system (the most common system in use today) the radix (base number) is t ...

'' spp.

References

Plagiorchiidae Animals described in 1800 Parasites of molluscs Parasites of insects Parasites of amphibians {{Trematoda-stub