Arhythmacanthidae is a family of parasitic worms from the order Echinorhynchida.
There are 9 genera in the family Arhythmacanthidae which contains the following species:
Acanthocephaloides <small>Meyer, 1932</small> contains 13 known species:
Found off Japan. The proboscis has 14 rows each of 6 hooks and 2 spines and the trunk has an anterior swelling. The apical hooks are the smallest; posterior hook largest, reaching up to 74 um. Hook and spine roots (when present) invariably simple, posteriorly directed, without manubria. Trunk spines are markedly smaller, with a variable distribution of trunk spines only on the anterior side.
A. cyrusi has been found parasitizing the fish: Blackhand sole (Pegusa nasuta referred to by its synonym Solea bleekeri) and the Small-spotted grunter (Pomadasys commersonnii) in Lake St. Lucia, Natal, South Africa. It is distinguished from the other species in the genus Arhythmacanthidae by the more greater sexual dimorphism in length, differing arrangement of hooks, the proboscis with the longest hooks at the anterior-most part and the larger size of proboscis hooks and body spines. Specifically, the proboscis hook rows with 3 spines and 3 hooks that increase in size anteriorly. Apical hook reaches 83âÂÂ101 or 118âÂÂ137 um in length and has root with large, oblique, anterior manubrium. Posterior spines rootless. Whole trunk with regular transverse rows of uniform, acuminate, 13âÂÂ22 um long spines.
Found off Senegal.
Found off the Mediterranean coast of France.
Found off Japan. The proboscis has variable 13âÂÂ14 (rarely 12 or 16) hook rows of 10âÂÂ12 hooks/spines (9 hooks and 3 rootless spines in 1 specimen). Hook and spine roots (when present) invariably simple, posteriorly directed, without manubria with the apical hook being the smallest; posterior hook largest, and reaching up to 74 um. The trunk is cylindrical and has spines only on the anterior portion smaller than proboscis hooks and variable in their distribution.
A. irregularis is found parasitizing the Combtooth blenny (Parablennius zvonimiri) in the Gulf of Odesa, Ukraine, the Mushroom goby (Ponticola eurycephalus) in the Sukhyi Estuary, in the Black Sea, and the Tubenose goby (Proterorhinus marmoratus) and Black-striped pipefish (Syngnathus abaster) in both locations. The species is named for its irregular distribution of trunk spines. A. irregularis is most similar to its closest relative, A. propinquus in proboscis shape and armature as both have 12 longitudinal rows of 5 hooks each and the shape of the trunk, reproductive system and lemnisci. A. irregularis differs from A. propinquus in having randomly distributed trunk spines that are organised in circular rings of individual spines separated by aspinose zones. A. irregularis is also unique in having an anterior trunk collar, a very large triangular cephalic ganglion, nucleated pouches at the posterior end of the proboscis receptacle, and hooks and spines with roots bearing anterior manubria. It is the tenth species of the genus to be described.
Found off Japan.
A. propinquus was found parasitizing Uranoscopus scaber, Gobius niger, Gobius cobitis, Merluccius merluccius, Scorpaena scrofa, Eutrigla gurnardus, and Solea solea in the bay of Gemlik, Turkey. It is also found in the Atlantic Ocean, Mediterranean Sea and Black Sea. The body is between 2600 and 6237 üm long and between 140 and 280 üm wide. The eggs were between 30 and 64 üm long and 10 to 16 üm wide.
Found off Japan.
Found off Puerto Rico.
Bolborhynchoides <small>Achmerov and Dombrovskaja-Achmerova, 1959</small> contains one species.
Breizacanthus <small>Golvan, 1969</small> contains five known species:
Infests the Striped red mullet (Mullus surmuletus).
Euzetacanthus <small>Golvan and Houin, 1964</small> contains three species:
Heterosentis <small>Van Cleave, 1931</small> contains 15 known species:
H. heteracanthus was found parasitizing Patagonotothen longipes, Patagonotothen tessellata and Champsocephalus esox in the eastern mouth of the Beagle Channel.
H. holospinus has been found parasitizing the Striped eel catfish (Plotosus lineatus), in Halong Bay, Vietnam.
Hypoechinorhynchus <small>Yamaguti, 1939</small> has five known species:
H. magellanicus was found parasitizing Champsocephalus esox in the eastern mouth of the Beagle Channel.
Worms in this Paracanthocephaloides <small>Golvan, 1969</small> have no trunk spines. There are four known species:
The proboscis hooks in Solearhynchus <small>de Buron and Maillard, 1985</small> gradually decrease in size posteriorly. There are only two known species
S. kostylewi was found parasitizing Solea solea in the bay of Gemlik, Turkey. The body was between 7404 and 7854 üm long and 739 and 1040 üm wide. The anterior part of the body was wider than the posterior. The proboscis was cylindrical and armed with 16 rows of hooks each with 5 or 6 hooks the longest hooks being in the middle of the proboscis. The smallest basal spinelike hooks were unrooted. The testes were located centrally in the body distant from the six cement glands. The eggs measured between 42 â 64üm long and between 12 and 20üm wide.
S. soleae was found parasitizing Solea solea in the bay of Gemlik, Turkey. The body was from 5382 to 20328 üm long and 693 to 1200 üm wide. The proboscis was from 224 â 320 üm long and the proboscis sac was between 277 and 480 üm long. The proboscis has 12 â 14 rows of hooks each comprising 5 or 6 hooks. The longest hooks were in the middle of the proboscis and the smallest basal hooks were unrooted and resembled spines. The lemnisci were longer than the proboscis sac, measuring between 312 and 350 üm and between 312 â 349 üm long. Males had two testes in the posterior part of the body distant from six piriform cement glands. The eggs measured between 56 and 68 üm long and between 12 and 20 üm wide. This species was also recorded in the Black Sea by Belofastova and Korniychuk (as the synonym Acanthocephaloides rhytidotes). The species name soleae derives from the genus name of the host, the Adriatic sole (Originannly named Solea impar, now named Pegusa impar).
Spiracanthus <small>Muñoz and George-Nascimento, 2002</small> has one species
Yamagutirhynchus has two species:
Arhythmacanthidae species parasitize fish.