Arhythmacanthidae

Arhythmacanthidae is a family of parasitic worms from the order Echinorhynchida.

Species
There are 9 genera in the family Arhythmacanthidae which contains the following species:

Acanthocephaloides
Acanthocephaloides Meyer, 1932 contains several species:


 * Acanthocephaloides claviformis Araki & Machida, 1987

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 83–101 or 118–137 um in length and has root with large, oblique, anterior manubrium. Posterior spines rootless. Whole trunk with regular transverse rows of uniform, acuminate, 13–22 um long spines. Found off Senegal. Found off the Mediterranean coast of France. Found off Japan. The proboscis has variable 13–14 (rarely 12 or 16) hook rows of 10–12 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 probiscus hooks and variable in their distribution.
 * Acanthocephaloides cyrusi Bray, Spencer-Jones & Lewis, 1988
 * Acanthocephaloides delamuri (Parukhin, 1989) Amin, 2013
 * Acanthocephaloides distinctus Golvan, 1969
 * Acanthocephaloides geneticus (Buron, Renaud & Euzet, 1985)
 * Acanthocephaloides ichiharai Araki & Machida, 1987

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.
 * Acanthocephaloides irregularis Amin, Oğuz, Heckman, Tepe & Kvach, 2011
 * Acanthocephaloides neobythitis (Yamaguti, 1939) Amin, 2013
 * Acanthocephaloides nicoli (Kumar, 1992) Amin, 2013
 * Acanthocephaloides plagiusae Santana-Pineros, Cruz-Quintana, Centeno-Chale & Vidal-Martinez, 2013
 * Acanthocephaloides propinquus (Dujardin, 1845)

A. propinquus was found parasitizing Uranoscopus scaber, Gobius niger, Gobius cobitis, Merluccius merluccius, Scorpaena scrofa, Eutrigla gurnardus, and Solea vulgaris 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 μm long and between 140 and 280 μm wide. The eggs were between 30 and 64 μm long and 10 to 16 μm wide.

Found off Japan. Found off Puerto Rico.
 * Acanthocephaloides rhinoplagusiae (Yamaguti, 1935) Amin, 2013
 * Acanthocephaloides spinicaudatus (Cable & Quick, 1954) Pichelin & Cribb, 1999

Bolborhynchoides
Bolborhynchoides Achmerov and Dombrovskaja-Achmerova, 1959 contains one species.
 * Bolborhynchoides exiguus (Achmerow & Dombrowskaja-Achmerova, 1941)

Breizacanthus
Breizacanthus Golvan, 1969 contains many species: Infests the Striped red mullet (Mullus surmuletus).
 * Breizacanthus aznari Hernández-Orts, Alama-Bermejo, Crespo, García, Raga & Montero, 2012
 * Breizacanthus chabaudi Golvan, 1969
 * Breizacanthus golvani Gaevskaja & Shukhgalter, 1984
 * Breizacanthus irenae Golvan, 1969
 * Breizacanthus ligur Paggi, Orecchia & Della Setta, 1975

Euzetacanthus
Euzetacanthus Golvan and Houin, 1964 contains three species:
 * Euzetacanthus chorinemusi Gupta & Naqvi, 1984
 * Euzetacanthus golvani Gupta & Fatma, 1985
 * Euzetacanthus simplex (Rudolphi, 1810)

Heterosentis
Heterosentis Van Cleave, 1931 contains several species:
 * Heterosentis brasiliensis Vieira, Felizardo & Luque, 2009
 * Heterosentis fusiformis (Yamaguti, 1935) Tripathi, 1959
 * Heterosentis heteracanthus (Linstow, 1896) Van Cleave, 1931

H. heteracanthus was found parasitizing Patagonotothen longipes, Patagonotothen tessellata and Champsocephalus esox in the eastern mouth of the Beagle Channel.


 * Heterosentis hirsutus Pichelin & Cribb, 1999
 * Heterosentis holospinus Amin, Heckman & Ha, 2011

H. holospinus has been found parasitizing the Striped eel catfish (Plotosus lineatus), in Halong Bay, Vietnam.


 * Heterosentis martini Lanfranchi & Timi, 2011
 * Heterosentis mongcai Amin, Heckmann & Ha, 2014
 * Heterosentis mysturi Wei, Huang, Chen and Jiang, 2002
 * Heterosentis overstreeti (Schmidt & Paperna, 1978) Amin, 1985
 * Heterosentis paraplagusiarum (Nickol, 1972) Amin, 1985
 * Heterosentis plotosi (Yamaguti, 1935) Schmidt & Paperna, 1978
 * Heterosentis septacanthus (Sita in Golvan, 1969) Amin, 1985
 * Heterosentis thapari (Gupta & Fatma, 1979) Amin, 1985
 * Heterosentis zdzitowieckii (Kumar, 1992) Pichelin & Cribb, 1999

Hypoechinorhynchus
Hypoechinorhynchus Yamaguti, 1939 has several species:
 * Hypoechinorhynchus alaeopis Yamaguti, 1939
 * Hypoechinorhynchus golvani Gutpa & Kumar, 1987
 * Hypoechinorhynchus magellanicus Szidat, 1950

H. magellanicus was found parasitizing Champsocephalus esox in the eastern mouth of the Beagle Channel.


 * Hypoechinorhynchus robustus Pichelin, 1999
 * Hypoechinorhynchus thermaceri Buron, 1988

Paracanthocephaloides
Worms in this Paracanthocephaloides Golvan, 1969 have no trunk spines.
 * Paracanthocephaloides caballeroi (Gupta & Fatma, 1983) Bhattacharya, 2007
 * Paracanthocephaloides chabanaudi (Dollfus, 1951)
 * Paracanthocephaloides incrassatus (Molin, 1858) Meyer, 1932
 * Paracanthocephaloides tripathii Golvan, 1969

Solearhynchus
The proboscis hooks in Solearhynchus de Buron and Maillard, 1985 gradually decrease in size posteriorly. S. kostylewi was found parasitizing Solea vulgaris in the bay of Gemlik, Turkey. The body was between 7404 and 7854 μm long and 739 and 1040 μm 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 – 64μm long and between 12 and 20μm wide.
 * Solearhynchus kostylewi (Meyer, 1932)


 * Solearhynchus soleae (Porta, 1905)

S. soleae was found parasitizing Solea vulgaris in the bay of Gemlik, Turkey. The body was from 5382 to 20328 μm long and 693 to 1200 μm wide. The proboscis was from 224 – 320 μm long and the proboscis sac was between 277 and 480 μm long. The proboscis has 12 – 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 μm and between 312 – 349 μm 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 μm long and between 12 and 20 μm 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
Spiracanthus Muñoz and George-Nascimento, 2002 has one species
 * Spiracanthus bovichthys Munoz & George-Nascimento, 2002

Yamagutirhynchus
Yamagutirhynchus has two species:
 * Yamagutirhynchus elliotae Smales 2023
 * Yamagutirhynchus lymberyi Smales 2023

Hosts
Arhythmacanthidae  species parasitize fish.