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Heterorhabditis caligo n. sp. (Rhabditida: Heterorhabditidae): A New Entomopathogenic Nematode from Pichilemu Sand Dunes, Chile Cover

Heterorhabditis caligo n. sp. (Rhabditida: Heterorhabditidae): A New Entomopathogenic Nematode from Pichilemu Sand Dunes, Chile

Open Access
|Nov 2025

Figures & Tables

Figure 1:

Light microscopy photographs of the hermaphrodite and amphimictic female of Heterorhabditis caligo n. sp. (A) anterior region of hermaphrodite, (B) anterior region of the amphimictic female, (C) detail of the head showing the labial papillae of hermaphrodites, (D) detail of the head showing the labial papillae of the amphimictic female, (E) detail of the vulva of the hermaphrodite, (F,G) tail variations of the hermaphrodites, (H) tail of the amphimictic female. Scale bars: A–D and F–H = 20 μm; E = 10 μm.
Light microscopy photographs of the hermaphrodite and amphimictic female of Heterorhabditis caligo n. sp. (A) anterior region of hermaphrodite, (B) anterior region of the amphimictic female, (C) detail of the head showing the labial papillae of hermaphrodites, (D) detail of the head showing the labial papillae of the amphimictic female, (E) detail of the vulva of the hermaphrodite, (F,G) tail variations of the hermaphrodites, (H) tail of the amphimictic female. Scale bars: A–D and F–H = 20 μm; E = 10 μm.

Figure 2:

Drawings of the hermaphrodite of Heterorhabditis caligo n. sp. (A) anterior region, (B) head region, (C) vulva; (D–F) Tail variations of the hermaphrodites, Scale bars: A–B and D–F = 20 μm; C = 10 μm.
Drawings of the hermaphrodite of Heterorhabditis caligo n. sp. (A) anterior region, (B) head region, (C) vulva; (D–F) Tail variations of the hermaphrodites, Scale bars: A–B and D–F = 20 μm; C = 10 μm.

Figure 3:

Light microscopy photographs of males of H. caligo n. sp. (A) anterior part of the male (B) male in toto; (C,D) Lateral and ventral view of papillary arrangement gubernaculum of first-generation male in ventral view; (E,F) tail showing spicula and gubernaculum shapes. Scale bars: A = 20 μm; B = 100 μm; C–F = 10 μm.
Light microscopy photographs of males of H. caligo n. sp. (A) anterior part of the male (B) male in toto; (C,D) Lateral and ventral view of papillary arrangement gubernaculum of first-generation male in ventral view; (E,F) tail showing spicula and gubernaculum shapes. Scale bars: A = 20 μm; B = 100 μm; C–F = 10 μm.

Figure 4:

Drawings of male and IJs of Heterorhabditis caligo n. sp. (A) anterior region of male; (B) head; (C) anterior region of IJ; (D) posterior portion of male in lateral view, showing spicules, gubernaculum and papillae arrangement; (E) posterior portion of male in ventral view, showing spicules, gubernaculum and papillae arrangement; (F) posterior portion of IJ showing amphids. Scale bars: A–B = 20 μm; C–F = 10 μm. IJs, infective juveniles.
Drawings of male and IJs of Heterorhabditis caligo n. sp. (A) anterior region of male; (B) head; (C) anterior region of IJ; (D) posterior portion of male in lateral view, showing spicules, gubernaculum and papillae arrangement; (E) posterior portion of male in ventral view, showing spicules, gubernaculum and papillae arrangement; (F) posterior portion of IJ showing amphids. Scale bars: A–B = 20 μm; C–F = 10 μm. IJs, infective juveniles.

Figure 5:

Light microscopy photographs of IJs of Heterorhabditis caligo n. sp. (A) anterior part showing bacterial cells in the intestine (arrow), (B) detail of the head showing the dorsal tooth, (C) genital primordium, (D) basal bulb showing subventral gland (arrow), (E) tessellate pattern of the cuticle, (F) tail showing phasmid (arrow). Scale bars = 10 μm. IJs, infective juveniles.
Light microscopy photographs of IJs of Heterorhabditis caligo n. sp. (A) anterior part showing bacterial cells in the intestine (arrow), (B) detail of the head showing the dorsal tooth, (C) genital primordium, (D) basal bulb showing subventral gland (arrow), (E) tessellate pattern of the cuticle, (F) tail showing phasmid (arrow). Scale bars = 10 μm. IJs, infective juveniles.

Figure 6:

Approximately-maximum-likelihood phylogenetic trees reconstructed from concatenated sequences of orthogroups of different Heterorhabditis species. A total of 4,600 single-copy orthogroups, comprising 1,846,787 amino acid positions, were analyzed. Numbers at the nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Heterorhabditis mexicana from the indica clade and H. marelatus from the megidis clade could not be included in the analyses due to lack of laboratory cultures.
Approximately-maximum-likelihood phylogenetic trees reconstructed from concatenated sequences of orthogroups of different Heterorhabditis species. A total of 4,600 single-copy orthogroups, comprising 1,846,787 amino acid positions, were analyzed. Numbers at the nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Heterorhabditis mexicana from the indica clade and H. marelatus from the megidis clade could not be included in the analyses due to lack of laboratory cultures.

Figure 7:

Maximum-likelihood phylogenetic tree reconstructed from concatenated sequences of the following protein-coding genes: cytochrome c oxidase, cytochrome b, and NADH dehydrogenase of the mitochondrial genomes of different Heterorhabditis species. A total of 9,494 nucleotide positions were analyzed. The genes were concatenated in the following order: cob, cox-1, cox-2, cox-3, nad-1, nad-2, nad-3, nad-4, nad-4l, nad-5, and nad-6. Accession numbers of the concatenated sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Heterorhabditis mexicana from the indica clade and H. marelatus from the megidis clade could not be included in the analyses due to lack of laboratory cultures.
Maximum-likelihood phylogenetic tree reconstructed from concatenated sequences of the following protein-coding genes: cytochrome c oxidase, cytochrome b, and NADH dehydrogenase of the mitochondrial genomes of different Heterorhabditis species. A total of 9,494 nucleotide positions were analyzed. The genes were concatenated in the following order: cob, cox-1, cox-2, cox-3, nad-1, nad-2, nad-3, nad-4, nad-4l, nad-5, and nad-6. Accession numbers of the concatenated sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Heterorhabditis mexicana from the indica clade and H. marelatus from the megidis clade could not be included in the analyses due to lack of laboratory cultures.

Figure 8:

Maximum-likelihood phylogenetic tree reconstructed from the whole ribosomal RNA operons of different Heterorhabditis species. A total of 5,927 nucleotide positions were analyzed. Accession numbers of the sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Heterorhabditis mexicana from the indica clade and H. marelatus from the megidis clade could not be included in the analyses due to lack of laboratory cultures.
Maximum-likelihood phylogenetic tree reconstructed from the whole ribosomal RNA operons of different Heterorhabditis species. A total of 5,927 nucleotide positions were analyzed. Accession numbers of the sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Heterorhabditis mexicana from the indica clade and H. marelatus from the megidis clade could not be included in the analyses due to lack of laboratory cultures.

Figure 9:

Maximum aphylogenetic tree reconstructed from the concatenated sequences of the ITS region of the rRNA gene and the cytochrome c oxidase subunit I (cox-1) gene of different Heterorhabditis species. A total of 1,482 nucleotide positions were analyzed. The ITS sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers AY321479 and EF043444, respectively. The ITS sequences of all the other isolates were extracted from whole ribosomal RNA operons. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers TW81 and AW28. The cox-1 sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers EF043419 and EF043422, respectively. The sequences of all the other isolates were extracted from whole mitochondrial genomes. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers HCF and HCR. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. ITS, internal transcribed spacer; NCBI, National Center for Biotechnology Information.
Maximum aphylogenetic tree reconstructed from the concatenated sequences of the ITS region of the rRNA gene and the cytochrome c oxidase subunit I (cox-1) gene of different Heterorhabditis species. A total of 1,482 nucleotide positions were analyzed. The ITS sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers AY321479 and EF043444, respectively. The ITS sequences of all the other isolates were extracted from whole ribosomal RNA operons. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers TW81 and AW28. The cox-1 sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers EF043419 and EF043422, respectively. The sequences of all the other isolates were extracted from whole mitochondrial genomes. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers HCF and HCR. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. ITS, internal transcribed spacer; NCBI, National Center for Biotechnology Information.

Figure 10:

Maximum-likelihood phylogenetic tree reconstructed from the nucleotide sequences of the calmodulin 1 (cmd-1) gene. A total of 738 nucleotide positions were analyzed. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Trees were rooted at the midpoint.
Maximum-likelihood phylogenetic tree reconstructed from the nucleotide sequences of the calmodulin 1 (cmd-1) gene. A total of 738 nucleotide positions were analyzed. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Trees were rooted at the midpoint.

Figure 11:

Maximum-likelihood phylogenetic tree reconstructed from the nucleotide sequences of the thin filament F-actin-associated protein (unc-87) gene. A total of 465 nucleotide positions were analyzed. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Trees were rooted at the midpoint.
Maximum-likelihood phylogenetic tree reconstructed from the nucleotide sequences of the thin filament F-actin-associated protein (unc-87) gene. A total of 465 nucleotide positions were analyzed. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. Trees were rooted at the midpoint.

Figure 12:

Phylogenetic reconstruction based on core genome sequences of Photorhabdus type strains with validly published names. A total of 3,526,609 nucleotide positions (3,455 core genes) were used in the analyses. Numbers at the nodes represent SH-like branch supports. Bar represents 0.05 nucleotide substitutions per sequence position. Accession numbers of the genome sequences used for the reconstruction are shown in Table S4 in the Supplementary Material.
Phylogenetic reconstruction based on core genome sequences of Photorhabdus type strains with validly published names. A total of 3,526,609 nucleotide positions (3,455 core genes) were used in the analyses. Numbers at the nodes represent SH-like branch supports. Bar represents 0.05 nucleotide substitutions per sequence position. Accession numbers of the genome sequences used for the reconstruction are shown in Table S4 in the Supplementary Material.

Figure S1:

Maximum-likelihood phylogenetic tree reconstructed from the sequences of the ITS region of the rRNA gene of different Heterorhabditis species. A total of 1075 nucleotide positions were analyzed. The sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers AY321479 and EF043444, respectively. The sequences of all the other isolates were extracted from whole ribosomal RNA operons. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers TW81 and AW28. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at the nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. ITS, internal transcribed spacer.
Maximum-likelihood phylogenetic tree reconstructed from the sequences of the ITS region of the rRNA gene of different Heterorhabditis species. A total of 1075 nucleotide positions were analyzed. The sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers AY321479 and EF043444, respectively. The sequences of all the other isolates were extracted from whole ribosomal RNA operons. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers TW81 and AW28. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at the nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position. ITS, internal transcribed spacer.

Figure S2:

Maximum-likelihood phylogenetic tree reconstructed from the sequences of the cytochrome c oxidase subunit I (cox-1) gene of different Heterorhabditis species. A total of 401 nucleotide positions were analyzed. The sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers EF043419 and EF043422, respectively. The sequences of all the other isolates were extracted from whole mitochondrial genomes. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers HCF and HCR. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at the nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position.
Maximum-likelihood phylogenetic tree reconstructed from the sequences of the cytochrome c oxidase subunit I (cox-1) gene of different Heterorhabditis species. A total of 401 nucleotide positions were analyzed. The sequences of H. marelatus and H. mexicana were obtained from the NCBI using the accession numbers EF043419 and EF043422, respectively. The sequences of all the other isolates were extracted from whole mitochondrial genomes. These sequences were then trimmed to obtain sequences that cover the region flanked by the commonly used primers HCF and HCR. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3 in the Supplementary Material. Numbers at the nodes represent bootstrap values based on 500 replications. Bars represent average nucleotide substitutions per sequence position.

Features and assemble statistics of the nematode genomes generated and/or used in this study_

SpeciesStrain designation(s)L50N50L90N90Genome size (bp)GC content (%)
H. amazonensisAPURE18594744692218066510168033.72
H. americanaS1043248365181564217278296833.07
S863533153288637357223471133.27
H. atacamensis3187321282969940124496722490732.98
3303121881903981114706740970033.09
Brecon58535417225164756988970832.85
EN0159335153263540577195966033.02
IR2422507081521106017020320132.90
m13e78727231303046977258599333.08
H. bacteriophoraMG618b63933083279140497186863133.02
NL42449858159795157107739233.14
S1259435368263741027187230633.00
SGI-17041550445180158337325077233.13
Px-SPH39653254177856747398496233.22
Z138354630165564797329300033.13
H. baujardiPUC-He-TD1166102718632232556466294333.73
PUC-He-TD221086004814156716617549733.60
Cherry38753208159579037196075932.97
H. beicherrianaCN474028317301143017079739532.83
H0658635927248848717074203732.82
M637855114160075337227656533.06

H. caligo n. sp.UOH-03221690000991116637219428433.78

H441052252177064137308052633.16
H. casmiricaHM41251774177164697303677933.15
HP149640787180893307015344132.94
H. downesiP2, pur258233455218966026629524933.33
P3, pur3344533551310116636514425033.18
H. floridensis33219592043712214596456102333.74
K2219094213711210756479006033.79
Hbb61734453271342097154387532.94
H. georgianaKesha43249201188059657292532833.06
Point Reyes42549428180364717252722433.03
AB, HeM22579854917126066568034933.80
Bartow247733851017104336630465833.86
H. indicaIARI, IARI-EPN-Hms173234422298601486754682732.34
LN2244744141018103326642739133.91
Rebecca22381088916118686593696933.83
H. megidisUK211234779321025113176672055133.23
H. noenieputensisSF66927266412118677696674092334.02
H. ruandicaRw18_M-Hr1a45646969207247057399459032.80
Rw18_M-Hr1b45148699205851437480799233.81
H. safricanaSF28118192924847122796694278833.06
H. taysearaeBenin23578313928122996699170734.04
H. zacatecanaMEX-3945046782186666297248978133.01
MEX-4161134263255848867102224532.85
H. zealandicaBlue, SF4128366513128083256761444933.11
Green, MJ2C21683151979108956706056633.09
Heterorhabditis sp.CRI-LC41050459163976867201700032.97

National Center for Biotechnology Information (NCBI) databank accession numbers of the nematode sequences used for phylogenetic reconstructions_

SpeciesStrain designation(s)Whole rRNA OperoncobPartialComplete
cox-1cox-1cox-2cox-3nad-1nad-2nad-3nad-4nad-4Inad-5nad-6unc-87cmd-1
H. amazonensisAPUREPQ345856PQ428464PQ368640PQ341126PQ428511PQ428558PQ428605PQ428652PQ428699PQ367523PQ428746PQ428793PQ428840PQ367570PQ367617
H. americanaS10PQ345891PQ428499PQ368684PQ341161PQ428546PQ428593PQ428640PQ428687PQ428734PQ367558PQ428781PQ428828PQ428875PQ367605PQ367652
S8PQ345893PQ428501PQ368683PQ341163PQ428548PQ428595PQ428642PQ428689PQ428736PQ367560PQ428783PQ428830PQ428877PQ367607PQ367654
H. atacamensis31873PQ345852PQ428460PQ368641PQ341122PQ428507PQ428554PQ428601PQ428648PQ428695PQ367519PQ428742PQ428789PQ428836PQ367566PQ367613
33031PQ345853PQ428461PQ368642PQ341123PQ428508PQ428555PQ428602PQ428649PQ428696PQ367520PQ428743PQ428790PQ428837PQ367567PQ367614
BreconPQ345860PQ428468PQ368643PQ341130PQ428515PQ428562PQ428609PQ428656PQ428703PQ367527PQ428750PQ428797PQ428844PQ367574PQ367621
EN01PQ345864PQ428472PQ368644PQ341134PQ428519PQ428566PQ428613PQ428660PQ428707PQ367531PQ428754PQ428801PQ428848PQ367578PQ367625
IR2PQ345872PQ428480PQ368645PQ341142PQ428527PQ428574PQ428621PQ428668PQ428715PQ367539PQ428762PQ428809PQ428856PQ367586PQ367633
H. bacteriophoram13e, TT01PQ345876PQ428484PQ368646PQ341146PQ428531PQ428578PQ428625PQ428672PQ428719PQ367543PQ428766PQ428813PQ428860PQ367590PQ367637
MG618bPQ345882PQ428490PQ368647PQ341152PQ428537PQ428584PQ428631PQ428678PQ428725PQ367549PQ428772PQ428819PQ428866PQ367596PQ367643
NLPQ345883PQ428491PQ368648PQ341153PQ428538PQ428585PQ428632PQ428679PQ428726PQ367550PQ428773PQ428820PQ428867PQ367597PQ367644
S12PQ345892PQ428500PQ368650PQ341162PQ428547PQ428594PQ428641PQ428688PQ428735PQ367559PQ428782PQ428829PQ428876PQ367606PQ367653
SGI-170, SGI170PQ345896PQ428504PQ368651PQ341166PQ428551PQ428598PQ428645PQ428692PQ428739PQ367563PQ428786PQ428833PQ428880PQ367610PQ367657
Px-SPH, PxSPHPQ345889PQ428497PQ368649PQ341159PQ428544PQ428591PQ428638PQ428685PQ428732PQ367556PQ428779PQ428826PQ428873PQ367603PQ367650
Z1PQ345898PQ428506PQ368652PQ341168PQ428553PQ428600PQ428647PQ428694PQ428741PQ367565PQ428788PQ428835PQ428882PQ367612PQ367659
H. baujardiPUC-He-TD1PQ345887PQ428495PQ368653PQ341157PQ428542PQ428589PQ428636PQ428683PQ428730PQ367554PQ428777PQ428824PQ428871PQ367601PQ367648
PUC-He-TD2PQ345888PQ428496PQ368654PQ341158PQ428543PQ428590PQ428637PQ428684PQ428731PQ367555PQ428778PQ428825PQ428872PQ367602PQ367649
CherryPQ345861PQ428469PQ368655PQ341131PQ428516PQ428563PQ428610PQ428657PQ428704PQ367528PQ428751PQ428798PQ428845PQ367575PQ367622
H. beicherrianaCN4PQ345862PQ428470PQ368656PQ341132PQ428517PQ428564PQ428611PQ428658PQ428705PQ367529PQ428752PQ428799PQ428846PQ367576PQ367623
H06PQ345866PQ428474PQ368657PQ341136PQ428521PQ428568PQ428615PQ428662PQ428709PQ367533PQ428756PQ428803PQ428850PQ367580PQ367627
M6PQ345877PQ428485PQ368658PQ341147PQ428532PQ428579PQ428626PQ428673PQ428720PQ367544PQ428767PQ428814PQ428861PQ367591PQ367638
H. caligo n. sp.UOH-032PV871102PV873291PV873292PV873292PV873293PV873294PV873295PV873296PV873297PV873298PV873300PV873299PV873301PV892898PV892895
H4PQ345867PQ428475PQ368659PQ341137PQ428522PQ428569PQ428616PQ428663PQ428710PQ367534PQ428757PQ428804PQ428851PQ367581PQ367628
H. casmiricaHMPQ345869PQ428477PQ368660PQ341139PQ428524PQ428571PQ428618PQ428665PQ428712PQ367536PQ428759PQ428806PQ428853PQ367583PQ367630
HP1PQ345870PQ428478PQ368661PQ341140PQ428525PQ428572PQ428619PQ428666PQ428713PQ367537PQ428760PQ428807PQ428854PQ367584PQ367631
H. downesiP2, pur2PQ345884PQ428492PQ368662PQ341154PQ428539PQ428586PQ428633PQ428680PQ428727PQ367551PQ428774PQ428821PQ428868PQ367598PQ367645
P3, pur3PQ345885PQ428493PQ368663PQ341155PQ428540PQ428587PQ428634PQ428681PQ428728PQ367552PQ428775PQ428822PQ428869PQ367599PQ367646
H. floridensis332PQ345854PQ428462PQ368664PQ341124PQ428509PQ428556PQ428603PQ428650PQ428697PQ367521PQ428744PQ428791PQ428838PQ367568PQ367615
K22PQ345873PQ428481PQ368665PQ341143PQ428528PQ428575PQ428622PQ428669PQ428716PQ367540PQ428763PQ428810PQ428857PQ367587PQ367634
HbbPQ345868PQ428476PQ368668PQ341138PQ428523PQ428570PQ428617PQ428664PQ428711PQ367535PQ428758PQ428805PQ428852PQ367582PQ367629
H. georgianaKeshaPQ345874PQ428482PQ368666PQ341144PQ428529PQ428576PQ428623PQ428670PQ428717PQ367541PQ428764PQ428811PQ428858PQ367588PQ367635
Point ReyesPQ345886PQ428494PQ368667PQ341156PQ428541PQ428588PQ428635PQ428682PQ428729PQ367553PQ428776PQ428823PQ428870PQ367600PQ367647
AB, HeMPQ345855PQ428463PQ368669PQ341125PQ428510PQ428557PQ428604PQ428651PQ428698PQ367522PQ428745PQ428792PQ428839PQ367569PQ367616
H. indicaBartowPQ345857PQ428465PQ368670PQ341127PQ428512PQ428559PQ428606PQ428653PQ428700PQ367524PQ428747PQ428794PQ428841PQ367571PQ367618
IARI, IARI-EPN-Hms1PQ345871PQ428479PQ368671PQ341141PQ428526PQ428573PQ428620PQ428667PQ428714PQ367538PQ428761PQ428808PQ428855PQ367585PQ367632
LN2PQ345875PQ428483PQ368672PQ341145PQ428530PQ428577PQ428624PQ428671PQ428718PQ367542PQ428765PQ428812PQ428859PQ367589PQ367636
RebeccaPQ345890PQ428498PQ368673PQ341160PQ428545PQ428592PQ428639PQ428686PQ428733PQ367557PQ428780PQ428827PQ428874PQ367604PQ367651
H. megidisUK211PQ345897PQ428505PQ368674PQ341167PQ428552PQ428599PQ428646PQ428693PQ428740PQ367564PQ428787PQ428834PQ428881PQ367611PQ367658
H. noenieputensisSF669PQ345895PQ428503PQ368675PQ341165PQ428550PQ428597PQ428644PQ428691PQ428738PQ367562PQ428785PQ428832PQ428879PQ367609PQ367656
H. ruandicaRw18_M-Hr1a, MaPQ345878PQ428486PQ368676PQ341148PQ428533PQ428580PQ428627PQ428674PQ428721PQ367545PQ428768PQ428815PQ428862PQ367592PQ367639
Rw18_M-Hr1b, MbPQ345879PQ428487PQ368677PQ341149PQ428534PQ428581PQ428628PQ428675PQ428722PQ367546PQ428769PQ428816PQ428863PQ367593PQ367640
H. safricanaSF281PQ345894PQ428502PQ368678PQ341164PQ428549PQ428596PQ428643PQ428690PQ428737PQ367561PQ428784PQ428831PQ428878PQ367608PQ367655
H. taysearaeBeninPQ345858PQ428466PQ368685PQ341128PQ428513PQ428560PQ428607PQ428654PQ428701PQ367525PQ428748PQ428795PQ428842PQ367572PQ367619
H. zacatecanaMEX-39, MEX39PQ345880PQ428488PQ368686PQ341150PQ428535PQ428582PQ428629PQ428676PQ428723PQ367547PQ428770PQ428817PQ428864PQ367594PQ367641
MEX-41, MEX41PQ345881PQ428489PQ368679PQ341151PQ428536PQ428583PQ428630PQ428677PQ428724PQ367548PQ428771PQ428818PQ428865PQ367595PQ367642
H. zealandicaBlue, SF41PQ345859PQ428467PQ368681PQ341129PQ428514PQ428561PQ428608PQ428655PQ428702PQ367526PQ428749PQ428796PQ428843PQ367573PQ367620
Green, MJ2CPQ345865PQ428473PQ368680PQ341135PQ428520PQ428567PQ428614PQ428661PQ428708PQ367532PQ428755PQ428802PQ428849PQ367579PQ367626
Heterorhabditis sp.CRI-LC, CRILCPQ345863PQ428471PQ368682PQ341133PQ428518PQ428565PQ428612PQ428659PQ428706PQ367530PQ428753PQ428800PQ428847PQ367577PQ367624

Features and annotation statistics of the nematode genomes generated and/or used in this study_

SpeciesStrain designation(s)BUSCO Genome assemblyNumber of proteinsBUSCO proteins
H. amazonensisAPURE831172582
H. americanaS10802014981
S8801836680
H. atacamensis31873821325675
33031821323981
Brecon811552571
EN01801924275
IR2811923377
m13e801908477
H. bacteriophoraMG618b801912781
NL801549081
S12801920081
SGI-170812115083
Px-SPH812438376
Z1812194975
H. baujardiPUC-He-TD1831156176
PUC-He-TD2831164874
Cherry822052880
H. beicherrianaCN4801377877
H06821738281
M6822528272

H. caligo n. sp.UOH-032821622380

H. casmiricaH4811829472
HM801837676
HP1801512471
H. downesiP2, pur2801223583
P3, pur3811225783
H. floridensis332831154182
K22831158776
Hbb801915681
H. georgianaKesha802330976
Point Reyes812035782
AB, HeM821282382
Bartow821305985
H. indicaIARI, IARI-EPN-Hms1841184481
LN2821308880
Rebecca831293381
H. megidisUK211821322480
H. noenieputensisSF669821341875
H. ruandicaRw18_M-Hr1a801844181
Rw18_M-Hr1b811827479
H. safricanaSF281821294775
H. taysearaeBenin832064770
H. zacatecanaMEX-39802495876
MEX-41812440281
H. zealandicaBlue, SF41822105781
Green, MJ2C832041782
Heterorhabditis sp.CRI-LC811981581

Morphometrics of Heterorhabditis caligo n_ sp_

CharacterMalesHermaphrodites ParatypesFemales ParatypesIJs Paratypes

HolotypeParatypes
n-20202020
L9671,018 ± 80 (864–1,174)3,616 ± 602 (2,855–4,950)2,674 ± 302 (2,002–3,103)669 ± 43 (568–723)
a20.119 ± 1.08 (16.9–20.8)14 ± 1.85 (11–18)15 ± 0.83 (13–17)27 ± 1.3 (23.7–29.1)
b8.39 ± 0.53 (7.7–9.5)16 ± 1.36 (13.5–19.19)16 ± 1.5 (13.1–19.6)5 ± 0.3 (4.2–5.2)
c32.231 ± 3.45 (24–38.9)40 ± 7.3 (27.7–55.2)2 ± 1.8 (2.4–0.13)6.8 ± 0.5 (5.4–7.7)
c′1.31 ± 0.18 (1.1–1.8)1.7 ± 0.33 (1.2–2.3)15 ± 2.2 (11.8–19.6)6 ± 0.4 (5.6–7.2)
V 46 ± 2.8 (40.3–50)52 ± 2.47 (45.6–56.8)
Max. body diam.4854 ± 4.1 (45–59)265 ± 39 (187–336)183 ± 20.2 (133–210)25 ± 1.5 (22–28)
Excretory pore124131 ± 7.7 (118–146)239 ± 37.9 (180–310)193 ± 16.5 (169–224)119 ± 6.3 (105–128)
Nerve ring7174 ± 6.4 (63–92)156 ± 29 (122–216)103 ± 15 (77–141)107 ± 4.2 (95–114)
Pharynx (ES)117118 ± 4.2 (112–126)224 ± 36.6 (175–294)173 ± 13.7 (148–197)141 ± 4 (135–150)
Hemizonoid 113 ± 4.0 (106–117)
Testis reflection128133 ± 29.1 (85–245)
Tail length3033 ± 4 (25–41)92 ± 11.9 (71–110)83 ± 7.3 (74–99)98 ± 9.7 (84–129)
Tail length without sheath 71 ± 5.1 (60–79)
Anal body diam.2423 ± 2.1 (21–27)55 ± 10.6 (40–75)42 ± 2.82 (38–50)16 ± 0.8 (15–18)
Spicule length5150 ± 3 (41–52)
Gubernaculum length2121 ± 1.1 (18–23)
D%106112 ± 6.7 (102–129) 84 ± 4.3 (75–91)
E%413403 ± 52.3 (367–535) 121 ± 4 (94–135)
SW%213214 ± 24.4 (152–248)
GS%4142 ± 3 (35–49)

Pairwise comparison of digital DNA–DNA Hybridization (dDDH) scores (%) of P_ tasmaniensis UOH-032 and all the Photorhabdus type strains with validly published names_ Accession numbers of gene sequences used are shown in Table S4_

StraindDDH (%)
P. aballayi sp. nov. APURET30.7
P. aegyptia BA1T31.5
P. africana CRI-LCT32.3
P. akhurstii subsp. akhurstii DSM 15138T31.2
P. akhurstii subsp. bharatensis H3T31.3
P. antumapuensis UCH-936T32.7
P. asymbiotica DSM 15149T30.7
P. australis subsp. australis DSM 17609T30.5
P. australis subsp. thailandensis PB68.1T30.8
P. bodei LJ24-63T32.6
P. caribbeanensis HG29T30.8
P. cinerea DSM 19724T31.7
P. hainanensis DSM 22397T31.1
P. heterorhabditis subsp. aluminescens Q614T32.7
P. heterorhabditis subsp. heterorhabditis SF41T31.7
P. hindustanensis H1T31.1
P. kayaii DSM 15194T32.6
P. khanii subsp. guanajuatensis MEX20-17T48.1
P. khanii subsp. khanii DSM 3369T47.6
P. kleinii DSM 23513T32
P. laumondii subsp. clarkei BOJ-47T32.1
P. laumondii subsp. laumondii TT01T31.9
P. luminescens subsp. luminescens ATCC 29999T30.8
P. luminescens subsp. mexicana MEX47-22T30.7
P. luminescens subsp. venezuelensis JART30.7
P. namnaonensis PB45.5T31.1
P. noenieputensis DSM 25462T31.1
P. stackebrandtii DSM 23271T47.1
P. tasmaniensis DSM 22387T85.3
P. temperata DSM 14550T51.1
P. thracensis DSM 15199T50.8
P. viridis GreenT49

National Center for Biotechnology Information (NCBI) accession numbers of the Photorhabdus sequences used in this study_ Sequences generated in this study are shown in bold_

StrainGenome
P. aballayi APURETJAPFCD01
P. africana CRI-LCTJAXBVE01
P. aegyptia BA1TJFGV01
P. akhurstii subsp. akhurstii DSM 15138TRCWE01
P. akhurstii subsp. bharatensis H3TPUWU01
P. antumapuensis UCH-936TJAHZMK01
P. australis subsp. thailandensis PB68.1TLOMY01
P. australis subsp. australis DSM 17609TJONO01
P. asymbiotica ATCC 43949TRBLJ01
P. bodei LJ24-63TNSCM01
P. caribbeanensis DSM 22391TRCWB01
P. cinerea DSM 19724TPUJW01
P. hainanensis DSM 22397TRCWD01
P. heterorhabditis subsp. aluminescens Q614TJABBCS01
P. heterorhabditis subsp. heterorhabditis SF41TRCWA01
P. hindustanensis H1TPUWT01
P. kayaii DSM 15194TJAJAFZ01
P. khanii subsp. khanii DSM 3369TAYSJ01
P. khanii subsp. guanajuatensis MEX20-17TPUJY01
P. kleinii DSM 23513TJAJAFY01
P. laumondii subsp. clarkei BOJ-47TNSCI01
P. laumondii subsp. laumondii TT01TWSFH01
P. luminescens subsp. luminescens ATCC 29999TFMWJ01
P. luminescens subsp. mexicana MEX47-22TPUJX01
P. luminescens subsp. venezuelensis JARTJAPFFZ01
P. namnaonensis PB45.5TLOIC01
P. noenieputensis DSM 25462TRCWC01
P. stackebrandtii DSM 23271TPUJV01
P. tasmaniensis DSM 22387TPUJU01
P. tasmaniensis UOH-32XXXXX
P. temperata DSM 14550TJAJAFX01
P. thracensis DSM 15199TCP011104
P. viridis GreenTJBEJZY01
DOI: https://doi.org/10.2478/jofnem-2025-0045 | Journal eISSN: 2640-396X | Journal ISSN: 0022-300X
Language: English
Submitted on: Jul 24, 2025
|
Published on: Nov 10, 2025
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2025 Ernesto San-Blas, Patricia Morales-Montero, Brynelly Bastidas, Vladimir Půža, Ricardo A. R. Machado, published by Society of Nematologists, Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.