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| Nematodes Genera A to B | Family |
Putative Feeding |
c-p Group |
Feeding Group |
Functional Guild |
Internal Code |
| Abathymermis | Mermithidae | animal parasites | G9552mnu.htm | |||
| Abbreviata | Physalopteridae | animal parasites | G9441mnu.htm | |||
| Abelbolla | Enchelidiidae | marine nematodes | G1506mnu.htm | |||
| Abirovulva | Carnoyidae | animal parasites | ||||
| Ablechroiulus | Rhabditidae | bacteria feeders | 1 | 3 | b1 | G2211mnu.htm |
| Aborjinia | Marimermithidae | marine parasites | ||||
| Abos | Benthimermithidae | animal parasites | ||||
| Abunema | Tripylidae | predators | 3 | 5 | p3 | |
| Acanthoatractis | Atractidae | animal parasites | G8653mnu.htm | |||
| Acanthocheilonema | Onchocercidae | animal parasites | G9882mnu.htm | |||
| Acantholaimus | Chromadoridae | marine nematodes | G4781mnu.htm | |||
| Acanthomicrolaimus | Microlaimidae | marine nematodes | ||||
| Acanthonchus | Cyatholaimidae | marine nematodes | G522mnu.htm | |||
| Acanthopharyngoides | Desmodoridae | marine nematodes | ||||
| Acanthopharynx | Desmodoridae | marine nematodes | G53212mnu.htm | |||
| Acanthorhabdias | Rhabdiasidae | animal parasites | ||||
| Acanthostrongylus | Heligmonellidae | animal parasites | G36315mnu.htm | |||
| Acanthoxyuris | Oxyuridae | animal parasites | ||||
| Acanthungella | Ungellidae | animal parasites | ||||
| Acephalodorylaimus | Encholaimidae | fungus feeders | 4 | 2 | f4 | G931mnu.htm |
| Achlysiella | Pratylenchidae | plant feeders | 3 | 1 | h3 | |
| Achromadora | Achromadoridae | eucaryote feeders | 3 | 6 | e3 | G501mnu.htm |
| Acontiolaimus | Camacolaimidae | marine nematodes | G432mnu.htm | |||
| Acontylus | Hoplolaimidae | plant feeders | 3 | 1 | h3 | G001mnu.htm |
| Acrobeles | Cephalobidae | bacteria feeders | 2 | 3 | b2 | G264mnu.htm |
| Acrobeloides | Cephalobidae | bacteria feeders | 2 | 3 | b2 | G265mnu.htm |
| Acrobelophis | Cephalobidae | bacteria feeders | 2 | 3 | b2 | G266mnu.htm |
| Acrolobus | Cephalobidae | bacteria feeders | 2 | 3 | b2 | G269mnu.htm |
| Acromoldavicus | Elaphonematidae | bacteria feeders | 2 | 3 | b2 | G2613mnu.htm |
| Acronema | Marimermithidae | marine parasites | ||||
| Acrostichus | Diplogastridae | bacteria feeders | 1 | 3 | b1 | G328mnu.htm |
| Acroukranicus | Cephalobidae | bacteria feeders | 2 | 3 | b2 | |
| Actarjania | Comesomatidae | marine nematodes | G5871mnu.htm | |||
| Actinca | Actinolaimidae | omnivores | 5 | 8 | o5 | G765mnu.htm |
| Actinolaimoides | Nordiidae | omnivores | 4 | 8 | o4 | G7131mnu.htm |
| Actinolaimus | Actinolaimidae | omnivores | 5 | 8 | o5 | G763mnu.htm |
| Actinonema | Chromadoridae | marine nematodes | G479mnu.htm | |||
| Actus | Mylonchulidae | predators | 4 | 5 | p4 | G657mnu.htm |
| Aculonchus | Leptonchidae | fungus feeders | 4 | 2 | f4 | G7792mnu.htm |
| Acunemella | Nordiidae | omnivores | 4 | 8 | o4 | G7135mnu.htm |
| Adelonema | Diplopeltidae | marine nematodes | ||||
| Adelphus | Desmodoridae | marine nematodes | ||||
| Adenodelphis | Benthimermithidae | animal parasites | ||||
| Adenolaimus | Aulolaimoididae | omnivores | 4 | 8 | o4 | G920mnu.htm |
| Adeuchromadora | Chromadoridae | marine nematodes | ||||
| Adieronema | Drilonematidae | animal parasites | ||||
| Admirandus | Oncholaimidae | marine nematodes | G15210mnu.htm | |||
| Adoncholaimus | Oncholaimidae | marine nematodes | G1529mnu.htm | |||
| Adungella | Ungellidae | animal parasites | ||||
| Aegialoalaimus | Aegialoalaimidae | marine nematodes | ||||
| Aelurostrongylus | Angiostrongylidae | animal parasites | ||||
| Aenigmenchus | Tylopharyngidae | fungus feeders | 2 | 2 | f2 | |
| Aequalodontium | Axonolaimidae | marine nematodes | ||||
| Aetholaimus | Nygolaimidae | predators | 5 | 5 | p5 | G671mnu.htm |
| Afenestrata | Heteroderidae | plant feeders | 3 | 1 | h3 | G002mnu.htm |
| Afractinca | Actinolaimidae | omnivores | 5 | 8 | o5 | G7651mnu.htm |
| Afractinolaimus | Actinolaimidae | omnivores | 5 | 8 | o5 | G7652mnu.htm |
| Africana | Heterakidae | animal paraqsites | ||||
| Africanastrongylus | Haemonchidae | animal parasites | ||||
| Africanema | Trefusiidae | marine nematodes | ||||
| Africanthion | Thoracostomopsidae | marine predators | ||||
| Afrina | Anguinidae | plant feeders | 2 | 1 | h2 | G165mnu.htm |
| Afrodorylaimus | Dorylaimidae | omnivores | 4 | 8 | o4 | G686mnu.htm |
| Afronygus | Nygolaimidae | predators | 5 | 5 | p5 | G670mnu.htm |
| Afrophilometra | Philometridae | animal parasites | ||||
| Agamermis | Mermithidae | animal parasites | ||||
| Agfa | Agfidae | animal parasites | G243mnu.htm | |||
| Aglenchus | Tylenchidae | plant feeders | 2 | 1 | h2 | G003mnu.htm |
| Agmodorus | Leptonchidae | fungus feeders | 4 | 2 | f4 | G7871mnu.htm |
| Agriostomum | Chabertiidae | animal parasites | ||||
| Agrochanus | Skrjabillanidae | animal parasites | G9416mnu.htm | |||
| Akanthepsilonema | Epsilonematidae | marine nematodes | G903mnu.htm | |||
| Akodonema | Angiostrongylidae | animal parasites | G9581mnu.htm | |||
| Akrotonus | Aporcelaimidae | omnivores | 5 | 8 | o5 | G7331mnu.htm |
| Alaeuris | Pharyngodonidae | |||||
| Alaimella | Camacolaimidae | marine nematodes | ||||
| Alaimonema | Desmodoridae | marine nematodes | ||||
| Alaimus | Alaimidae | bacteria feeders | 4 | 3 | b4 | G631mnu.htm |
| Alaninema | Drilonematidae | animal parasites | ||||
| Albiziaphelenchus | Aphelenchoididae | fungus feeders | 2 | 2 | f2 | |
| Algoanema | Chromadoridae | marine nematodes | ||||
| Aliascaris | Heterocheilidae | animal parasites | ||||
| Alirhabditis | Alirhabditidae | bacterial feeders | 1 | 3 | b1 | G305mnu.htm |
| Allantonema | Allantonematidae | animal parasites | ||||
| Allgenia | Linhomoiedae | marine nematodes | ||||
| Allintoshius | Ornithostrongylidae | animal parasites | ||||
| Allodiplogaster | Diplogastridae | |||||
| Allodorylaimus | Qudsianematidae | predators | 4 | 5 | p4 | G723mnu.htm |
| Alloionema | Alloionematidae | bacteria feeders | 1 | 3 | b1 | G230mnu.htm |
| Allomermis | Mermithidae | animal parasites | ||||
| Allotrichodorus | Trichodoridae | plant feeders | 4 | 1 | h3 | G146mnu.htm |
| Allotylenchus | Tylenchidae | plant feeders | 2 | 1 | h2 | G004mnu.htm |
| Alocostoma | Chabertiidae | animal parasites | ||||
| Amblydorylaimus | Aporcelaimidae | predators | 4 | 5 | p4 | G7233mnu.htm |
| Amidostomoides | Trichostrongylidae | animal parasites | ||||
| Amidostomum | Trichostrongylidae | animal parasites | G1105mnu.htm | |||
| Ammotheristus | Xyalidae | marine nematodes | G3834mnu.htm | |||
| Amphibelondira | Belondiridae | unkmown | G7541mnu.htm | |||
| Amphibiomermis | Mermithidae | animal parasites | ||||
| Amphibiophilus | Amphibiophilidae | animal parasites | ||||
| Amphicephaloides | Herpetostrongylidae | animal parasites | ||||
| Amphidelus | Amphidelidae | bacteria feeders | 4 | 3 | b4 | G632mnu.htm |
| Amphidirhabditis | Rhabditidae | bacteria feeders | G2286mnu.htm | |||
| Amphidomermis | Mermithidae | animal parasites | ||||
| Amphidorylaimus | Dorylaimidae | omnivores | 4 | 8 | o4 | G689mnu.htm |
| Amphimermis | Mermithidae | animal parasites | G9551mnu.htm | |||
| Amphimonhystera | Xyalidae | marine nematodes | G3831mnu.htm | |||
| Amphimonhystrella | Xyalidae | marine nematodes | G3832mnu.htm | |||
| Amphisbaenema | Criconematidae | plant feeders | 3 | 1 | h3 | G0231mnu.htm |
| Amplimerlinius | Merliniidae | plant feeders | 3 | 1 | h3 | G005mnu.htm |
| Anadorella | Thornenematidae | omnivores | 5 | 8 | o5 | G7081mnu.htm |
| Anandranema | Allantonematidae | animal parasites | ||||
| Ananus | Marimermithidae | marine parasites | ||||
| Anaplectus | Plectidae | bacteria feeders | 2 | 3 | b2 | G421mnu.htm |
| Anatonchus | Anatonchidae | predators | 4 | 5 | p4 | G660mnu.htm |
| Anatrichosoma | Trichosomoididae | animal parasites | G9251mnu.htm | |||
| Anchidiplogaster | Diplogastridae | |||||
| Anchobelondira | Belondiridae | unknown | G7512mnu.htm | |||
| Ancistronema | Chabertiidae | animal parasites | ||||
| Ancylostoma | Ancylostomatidae | animal parasites | G960mnu.htm | |||
| Andersonstrongylus | Angiostrongylidae | animal parasites | G95890mnu.htm | |||
| Andrassya | Andrassyidae | marine nemayodes | G592mnu.htm | |||
| Angiocaulus | Angiostrongylidae | animal parasites | ||||
| Angiostoma | Angiostomatidae | animal parasites | G235mnu.htm | |||
| Angiostrongylus | Angiostrongylidae | animal parasites | G958mnu.htm | |||
| Anguillicola | Anguillicolidae | animal parasites | ||||
| Anguillicoloides | Anguillicolidae | animal parasites | ||||
| Anguillonema | Neotylenchidae | fungus feeders | 2 | 2 | f2 | G1490mnu.htm |
| Anguilluloides | Panagrolaimidae | bacteria feeders | 1 | 3 | b1 | |
| Anguimonhystera | Monhysteridae | marine nematodes | ||||
| Anguina | Anguinidae | plant feeders | 2 | 1 | h2 | G006mnu.htm |
| Anguinoides | Camacolaimidae | marine nematodes | ||||
| Angulocirrus | Molineidae | animal parasites | ||||
| Angusticaecum | Ascarididae | animal parasite | ||||
| Anisakis | Anisakidae | animal parasites | G910mnu.htm | |||
| Anivanema | Leptosomatidae | marine nematodes | G5903mnu.htm | |||
| Anomalostoma | Hystrignathidae | animal parasites | ||||
| Anomonema | Leptolaimidae | marine nematodes | G4331mnu.htm | |||
| Anomyctus | Aphelenchoididae | fungus feeders | 2 | 2 | f2 | G2121mnu.htm |
| Anonchus | Aphanolaimidae | bacteria feeders | 3 | 3 | b3 | G4421mnu.htm |
| Anoplostoma | Anoplostomatidae | marine nematodes | G854mnu.htm | |||
| Anoplostrongylus | Molineidae | animal parasites | G357mnu.htm | |||
| Ansiruptodera | Aspidoderidae | animal parasites | ||||
| Antarctenchus | Tylenchidae | plant feeders | 2 | 1 | h2 | G007mnu.htm |
| Antarcticonema | Desmoscolecidae | marine nematodes | G9082mnu.htm | |||
| Antarctylus | Hoplolaimidae | plant feeders | 3 | 1 | h3 | G008mnu.htm |
| Antechinostrongylus | Angiostrongylidae | animal parasites | ||||
| Antholaimus | Qudsianematidae | predators | 4 | 5 | p4 | G7711mnu.htm |
| Anticoma | Anticomidae | marine nematodes | G850mnu.htm | |||
| Anticomopsis | Anticomidae | marine nematodes | ||||
| Anticyathus | Linhomoeidae | marine nematodes | G4013mnu.htm | |||
| Anticyclus | Linhomoeidae | marine nematodes | ||||
| Antomicron | Leptolaimidae | marine nematodes | G4332mnu.htm | |||
| Antopus | Anticomidae | marine nematodes | ||||
| Anuronema | Hystrignathidae | animal parasites | ||||
| Aonchotheca | Capillariidae | |||||
| Aorolaimus | Hoplolaimidae | plant feeders | 3 | 1 | h3 | G009mnu.htm |
| Aoruroides | Thelastomatidae | animal parasites | ||||
| Aorurus | Thelastomatidae | animal parasites | ||||
| Aphanolaimus | Aphanolaimidae | bacteria feeders | 3 | 3 | b3 | G442mnu.htm |
| Aphanonchus | Aphanolaimidae | bacteria feeders | 3 | 3 | b3 | G443mnu.htm |
| Aphasmatylenchus | Hoplolaimidae | plant feeders | 3 | 1 | h3 | G010mnu.htm |
| Aphelenchoides | Aphelenchoididae | fungus feeders | 2 | 2 | f2 | G011mnu.htm |
| Aphelenchulus | Allantonematidae | animal parasites | ||||
| Aphelenchus | Aphelenchidae | fungus feeders | 2 | 2 | f2 | G012mnu.htm |
| Aplectana | Cosmocercidae | animal parasites | G8606mnu.htm | |||
| Apodontium | Axonolaimidae | marine nematodes | ||||
| Apodorylaimus | Dorylaimidae | omnivores | 4 | 8 | o4 | G6861mnu.htm |
| Apoleptonchus | Leptonchidae | fungus feeders | 4 | 2 | f4 | G7831mnu.htm |
| Aponchium | Aponchiidae | marine nematodes | ||||
| Aponcholaimus | Linhomoeidae | marine nematodes | ||||
| Aponema | Microlaimidae | marine nematodes | G9152mnu.htm | |||
| Aporcedorus | Aporcelaimidae | omnivores | 5 | 8 | o5 | G7371mnu.htm |
| Aporcelaimellus | Aporcelaimidae | omnivores | 5 | 8 | o5 | G733mnu.htm |
| Aporcelaimium | Aporcelaimidae | omnivores | 5 | 8 | o5 | G734mnu.htm |
| Aporcelaimoides | Aporcelaimidae | omnivores | 5 | 8 | o5 | G7361mnu.htm |
| Aporcelaimus | Aporcelaimidae | omnivores | 5 | 8 | o5 | G735mnu.htm |
| Aporcelinus | Aporcelaimidae | omnivores | 5 | 8 | o5 | G769mnu.htm |
| Aporcella | Aporcelaimidae | omnivores | 5 | 8 | o5 | G737mnu.htm |
| Apratylenchoides | Pratylenchidae | plant feeders | 3 | 1 | h3 | G013mnu.htm |
| Apratylenchus | Pratylenchidae | plant feeders | 3 | 1 | h3 | G1441mnu.htm |
| Aprocta | Aproctidae | animal parasites | ||||
| Aproctoides | Aproctidae | animal parasites | ||||
| Aproctonema | Tetradonematidae | animal parasites | ||||
| Aprutides | Aphelenchoididae | fungus feeders | 2 | 2 | f2 | G212mnu.htm |
| Aquatides | Nygolaimidae | predators | 5 | 5 | p5 | G674mnu.htm |
| Araeolaimus | Diplopeltidae | marine nematodes | G450mnu.htm | |||
| Araguanema | Drilonematidae | animal parasites | G1516mnu.htm | |||
| Arboritynchus | Tylenchidae | plant feeders | 2 | 1 | h2 | G0301mnu.htm |
| Archeostrongylus | Syngamidae | animal parasites | ||||
| Archepsilonema | Epsilonematidae | marine nematodes | G905mnu.htm | |||
| Arctidorylaimus | Qudsianematidae | predators | 4 | 5 | p4 | G7232mnu.htm |
| Arctiplectus | Plectidae | bacteria feeders | 2 | 3 | b2 | |
| Arganema | Leptonchidae | fungus feeders | 4 | 2 | f4 | G780mnu.htm |
| Arnfieldia | Trichostrongylidae | animal parasites | ||||
| Aronema | Enchelidiidae | marine nematodes | ||||
| Arthrostoma | Ancylostomatidae | animal parasites | ||||
| Artigasia | Hystrignathidae | animal parasites | ||||
| Arundelia | Chabertiidae | animal parasites | ||||
| Aruroides | Thelastomatidae | animal parasites | ||||
| Ascaridia | Ascaridiidae | animal parasites | G9383mnu.htm | |||
| Ascaris | Ascarididae | animal parasites | G937mnu.htm | |||
| Ascarophis | Cystidicolidae | animal parasites | G9721mnu.htm | |||
| Ascarophisnema | Cystidicolidae | animal parasites | ||||
| Ascarops | Spirocercidae | animal parasites | G99011mnu.htm | |||
| Ascolaimus | Axonolaimidae | marine nematodes | ||||
| Ashworthus | Haemonchidae | animal parasites | ||||
| Asperotobrilus | Tobrilidae | predators | 3 | 5 | p3 | |
| Aspicularis | Heteroxynematidae | animal parasites | G9968mnu.htm | |||
| Aspidodera | Aspidoderidae | animal parasites | G9515mnu.htm | |||
| Aspidonema | Bunonematidae | bacteria feeders | 1 | 3 | b1 | G254mnu.htm |
| Astomonema | Siphonolaimidae | marine nematodes | G404mnu.htm | |||
| Asymmelaimus | Comesomatidae | marine nematodes | ||||
| Asymmetracantha | Mackerrastrongylidae | animal parasites | ||||
| Asymmetrella | Oncholaimidae | marine nematodes | ||||
| Atalodera | Heteroderidae | plant feeders | 3 | 1 | h3 | G014mnu.htm |
| Atetylenchus | Tylenchidae | plant feeders | 2 | 1 | h2 | G015mnu.htm |
| Athernema | Mydonomidae | fungus feeders | 4 | 2 | f4 | G7801mnu.htm |
| Athusia | Drilonematidae | animal parasites | ||||
| Atractis | Atractidae | animal parasites | G8655mnu.htm | |||
| Atrochromadora | Chromadoridae | marine nematodes | ||||
| Atylenchus | Tylenchidae | plant feeders | 2 | 1 | h2 | G016mnu.htm |
| Auanema | Rhabditidae | bacteria feeders | 1 | 3 | b1 | G899mnu.htm |
| Aulachnema | Angiostomatidae | animal parasites | G2351mnu.htm | |||
| Aulolaimoides | Aulolaimoididae | omnivores | 3 | 8 | o3 | G921mnu.htm |
| Aulolaimus | Aulolaimidae | bacteria feeders | 3 | 3 | b3 | G561mnu.htm |
| Aulostomonema | Linhomoeidae | marine nematodes | ||||
| Australodorus | Longidoridae | plant feeders | 5 | 1 | h5 | G069mnu.htm |
| Australonema | Marimermithidae | marine parasites | ||||
| Austraplectana | Cosmocercidae | animal parasites | G8608mnu.htm | |||
| Austrostrongylus | Herpetostrongylidae | animal parasites | G358mnu.htm | |||
| Austroxyuris | Oxyuridae | animal parasites | ||||
| Avellaria | Viannaiidae | animal parasites | ||||
| Avioserpens | Dracunculidae | animal parasites | ||||
| Axodorylaimellus | Dorylaimellidae | plant feeders | 5 | 1 | h5 | G7521mnu.htm |
| Axonchium | Belondiridae | plant feeders | 5 | 1 | h5 | G751mnu.htm |
| Axonchoides | Belondiridae | unknown | G754mnu.htm | |||
| Axonolaimus | Axonolaimidae | marine nematodes | G4502mnu.htm | |||
| Bainechina | Seuratidae | animal parasites | ||||
| Bakeria | Molineidae | animal parasites | G9641mnu.htm | |||
| Bakernema | Criconematidae | plant feeders | 3 | 3 | h3 | G017mnu.htm |
| Baladorylaimus | Dorylaimidae | omnivores | 4 | 8 | o4 | G683mnu.htm |
| Baldwinema | Panagrolaimidae | bacteria feeders | 1 | 3 | b1 | G287mnu.htm |
| Baqriella | Qudsianematidae | predators | 4 | 5 | p4 | G7234mnu.htm |
| Barbonema | Leptosomatidae | marine nematodes | G5891mnu.htm | |||
| Baruscapillaria | Capillariidae | animal parasites | G9491mnu.htm | |||
| Basilaphelenchus | Aphelenchoididae | fungus feeders | 2 | 2 | f2 | G2194mnu.htm |
| Basiliophora | Tylenchidae | plant feeders | 2 | 1 | h2 | |
| Basiria | Tylenchidae | plant feeders | 2 | 1 | h2 | G019mnu.htm |
| Basirienchus | Tylenchidae | plant feeders | 2 | 1 | h2 | G020mnu.htm |
| Basirotyleptus | Leptonchidae | fungus feeders | 4 | 2 | f4 | G7823mnu.htm |
| Bastiania | Bastianiidae | bacteria feeders | 3 | 3 | b3 | G618mnu.htm |
| Bathyepsilonema | Epsilonematidae | marine nematodes | G906mnu.htm | |||
| Bathyeurystomina | Enchelidiidae | marine nematodes | G1505mnu.htm | |||
| Bathylaimella | Linhomoeidae | marine nematodes | ||||
| Bathylaimus | Tripyloididae | |||||
| Bathynema | Benthimermithidae | animal parasites | ||||
| Bathynox | Microlaimidae | marine nematodes | ||||
| Bathyodontus | Bathyodontidae | predators | 4 | 5 | p5 | G641mnu.htm |
| Batrachocamallanus | Camallanidae | animal parasites | ||||
| Batrachonema | Amphibiophilidae | animal parasites | ||||
| Batrachostrongylus | Molineidae | animal parasites | ||||
| Baujardia | Panagrolaimidae | bacteria feeders | 1 | 3 | b1 | G289mnu.htm |
| Baylisascaris | Ascarididae | animal parasite | G938mnu.htm | |||
| Bealius | Sphaerulariidae | fungus feeders | ||||
| Beaninema | Rhabdochonidae | animal parasites | ||||
| Belaxellus | Belondiridae | unknown | G7542mnu.htm | |||
| Belbolla | Enchelidiidae | marine nematodes | G1500mnu.htm | |||
| Bellodera | Heteroderidae | plant feeders | 3 | 1 | h3 | G020mnu.htm |
| Belondirella | Belondiridae | plant feeders | 5 | 1 | h5 | G7573mnu.htm |
| Belondira | Belondiridae | plant feeders | 5 | 1 | h5 | G757mnu.htm |
| Belonolaimus | Dolichodoridae | plant feeders | 3 | 1 | h1 | G022mnu.htm |
| Bendiella | Selachinematidae | marine nematodes | G4914mnu.htm | |||
| Benthimermis | Benthimermithidae | animal parasites | ||||
| Bernardius | Enchelidiidae | omnivores | 4 | 8 | o4 | G1501mnu.htm |
| Bertzuckermania | Leptonchidae | fungus feeders | 4 | 2 | f4 | G7824mnu.htm |
| Betulodera | Heteroderidae | plant feeders | 3 | 1 | h3 | G0281mnu.htm |
| Beveridgea | Chabertiidae | animal parasites | ||||
| Beveridgiella | Herpetostrongylidae | animal parasites | ||||
| Biacantha | Molineidae | animal parasites | ||||
| Biarmifer | Cyatholaimidae | marine nematodes | G5226mnu.htm | |||
| Bicirronema | Bicirronematidae | bacteria feeders | 2 | 3 | b2 | G918mnu.htm |
| Bidentostomum | Strongylidae | animal parasites | ||||
| Bidigicaudata | Molineidae | animal parasites | ||||
| Bilobodera | Heteroderidae | plant feeders | 3 | 1 | h3 | |
| Bilobostoma | Thelastomatidae | animal parasites | ||||
| Binema | Travassosinematidae | animal parasites | G97510mnu.htm | |||
| Biogastranema | Cooperiidae | animal parasites | ||||
| Bispiculum | Tetradonematidae | animal parasites | ||||
| Bitylenchus | Telotylenchidae | plant feeders | 3 | 1 | h3 | G170mnu.htm |
| Blandicephalonema | Criconematidae | plant feeders | 3 | 1 | h3 | G023mnu.htm |
| Blatticola | Thelastomatidae | animal parasites | G9752mnu.htm | |||
| Blattophila | Thelastomatidae | animal parasites | ||||
| Blazionema | Thelastomatidae | animal parasites | ||||
| Bloberinema | Thelastomatidae | animal parasites | ||||
| Bodonema | Bodonematidae | marine nematodes | ||||
| Boehmiella | Boehmiellidae | animal parasites | G360mnu.htm | |||
| Bolbolaimus | Microlaimidae | marine nematodes | ||||
| Bolbonema | Desmodoridae | marine nematodes | G53213mnu.htm | |||
| Boleodorus | Tylenchidae | plant feeders | 2 | 1 | h2 | G024mnu.htm |
| Bongersia | Leptosomatidae | marine nematodes | G5892mnu.htm | |||
| Boomerangia | Tylenchulidae | plant feeders | G1361mnu.htm | |||
| Boracelanema | Hystrignathidae | animal parasites | ||||
| Borellostrongylus | Molineidae | animal parasites | ||||
| Boreolaimus | Qudsianematidae | predators | 4 | 5 | p4 | G7231mnu.htm |
| Boreomicrolaimoides | Linhomoeidae | marine nematodes | ||||
| Boucherius | Meyliidae | marine nematodes | G414mnu.htm | |||
| Bourgelatia | Chabertiidae | animal parasites | ||||
| Bourgelatioides | Chabertiidae | animal parasites | ||||
| Bovienema | Allantonematidae | animal parasites | ||||
| Boydinema | Syngamidae | animal parasites | ||||
| Brachonchulus | Mylonchulidae | predators | 4 | 5 | p4 | G649mnu.htm |
| Brachydorus | Dolichodoridae | plant feeders | 3 | 1 | h3 | G025mnu.htm |
| Bradylaimus | Desmodoridae | marine nematodes | ||||
| Bradynema | Allantonematidae | animal parasites | G3941mnu.htm | |||
| Bradypostrongylus | Molineidae | animal parasites | ||||
| Brasilaimus | Actinolaimidae | omnivores | 4 | 8 | o4 | G764mnu.htm |
| Brevibucca | Brevibuccidae | bacteria feeders | 1 | 3 | b1 | |
| Brevimulticaecum | Heterocheilidae | animal parasites | G1088mnu.htm | |||
| Brevistoma | Panagrolaimidae | bacteria feeders | 1 | 3 | b1 | |
| Brevistriata | Heligmonellidae | animal parasites | ||||
| Brevitobrilus | Tobrilidae | predators | 3 | 5 | p3 | |
| Brittonema | Actinolaimidae | omnivores | 4 | 8 | o4 | G7653mnu.htm |
| Bronchonema | Dictyocaulidae | animal parasites | ||||
| Brugia | Onchocercidae | animal parasites | G985mnu.htm | |||
| Brumptaemilius | Carnoyidae | animal parasites | ||||
| Brygoonema | Molineidae | animal parasites | ||||
| Buckleyatractis | Atractidae | animal parasites | G8652mnu.htm | |||
| Buckleynema | Quimperiidae | animal parasites | ||||
| Buetschlinema | Rhabditidae | bacteria feeders | 1 | 3 | b1 | G2223mnu.htm |
| Bulbodacnitis | Cucullanidae | animal parasites | ||||
| Bullaenema | Belondiridae | unknown | G7574mnu.htm | |||
| Bunomystrongylus | Heligmonellidae | animal parasites | ||||
| Bunonema | Bunonematidae | bacteria feeders | 1 | 3 | b1 | G251mnu.htm |
| Bunostomum | Ancylostomatidae | animal parasites | G9611mnu.htm | |||
| Burmanema | Drilonematidae | animal parasites | ||||
| Bursadera | Heteroderidae | plant feeders | 3 | 1 | h3 | G026mnu.htm |
| Bursaphelenchus | Aphelenchoididae | plant feeders | 2 | 1 | h2 | G145mnu.htm |
| Bursilla | Rhabditidae | bacteria feeders | 1 | 3 | b1 | G226mnu.htm |
| Butlerius | Diplogastridae | bacteria feeders | 1 | 3 | b1 | G323mnu.htm |