Conserved nuclear hormone receptors controlling a novel plastic trait target fast-evolving genes expressed in a single cell.

Environment shapes development through a phenomenon called developmental plasticity. Deciphering its genetic basis has potential to shed light on the origin of novel traits and adaptation to environmental change. However, molecular studies are scarce, and little is known about molecular mechanisms associated with plasticity. We investigated the gene regulatory network controlling predatory vs. non-predatory dimorphism in the nematode Pristionchus pacificus and found that it consists of genes of extremely different age classes. We isolated mutants in the conserved nuclear hormone receptor nhr-1 with previously unseen phenotypic effects. They disrupt mouth-form determination and result in animals combining features of both wild-type morphs. In contrast, mutants in another conserved nuclear hormone receptor nhr-40 display altered morph ratios, but no intermediate morphology. Despite divergent modes of control, NHR-1 and NHR-40 share transcriptional targets, which encode extracellular proteins that have no orthologs in Caenorhabditis elegans and result from lineage-specific expansions. An array of transcriptional reporters revealed co-expression of all tested targets in the same pharyngeal gland cell. Major morphological changes in this gland cell accompanied the evolution of teeth and predation, linking rapid gene turnover with morphological innovations. Thus, the origin of feeding plasticity involved novelty at the level of genes, cells and behavior.

First report of Caenorhabditis brenneri (Nematoda: Rhabditida) isolated from the cadaver of Philippinella moellendorffi (Stylommatophora: Ariophantidae), a terrestrial slug in the Philippines.

Gastropod-associated nematodes have been previously studied and documented worldwide, with some species forming host-specific association as obligate parasites of molluscs while others form intermediate and temporary association. Philippinella moellendorffi from Imelda, Zamboanga Sibugay, Philippines, were collected, washed and maintained in the laboratory until death. Cadavers were placed on nutrient agar to allow nematode proliferation. Nematode pure culture was obtained using one gravid female for propagation. Morphology and molecular analyses (18S ribosomal DNA (rDNA) and D2-D3 expansion segments of 28S rDNA) were employed as diagnostic tools in identifying the nematode species isolated from P. moellendorffi. The newly isolated nematode was identified as Caenorhabditis brenneri, thus designated as C. brenneri strain IZSP from the Philippines. This is the first record of C. brenneri isolated from the terrestrial slug P. moellendorffi.

Description of Hemicycliophora cardamomi sp. n. (Nematoda: Hemicycliophoridae) associated with Amomum longiligulare T.L. Wu and a web-based key for the identification of Hemicycliophora spp.

During a survey of plant diseases in the Central Highlands of Vietnam, a new plant-parasitic nematode, Hemicycliophora cardamomi sp. n., was discovered in the growing areas of Amomum longiligulare, a valuable medicinal plant with high economical value. The new species is characterized by a cuticular sheath loosely fitting body; a labial region continuous to the body contour bearing 3 annuli; a lateral field frequently marked by a discontinuous single line with indistinct additional short lines in some parts along the body; a modified vulval lip with an anterior lip c. 4 annuli long; and a post-vulval body tapering to a pointed tail tip with an abrupt constriction at the last third of the post-vulval body. Morphology and molecular characterizations of D2-D3 expansion segment of 28S rRNA, ITS, and COI mtDNA gene regions clearly distinguish the new species from all other 133 known species. This study also provides a newly developed web-based key for the identification of Hemicycliophora spp. in order to accelerate the identification process, to minimize the increasing error load associated with larger datasets, and to avoid any dependence on a single starting entry. This key includes both an existing Bray-Curtis similarity measure and a newly developed similarity formula.

Redescription of Macrolaimus canadensis Sanwal, 1960 and M. ruehmi Andrássy, 1966 (Nematoda, Rhabditida, Chambersiellidae), and new data on M. crucis Maupas, 1900.

Three species belonging to the genus Macrolaimus, namely M. canadensis, M. crucis and M. ruehmi, have been obtained from areas of natural vegetation in Bosnia and Herzegovina, Corsica (France), the Czech Republic and Spain. These three species are characterized by the body length of males and females, stomatal proportion of the gymnostom and cheilostom, excretory pore position, postvulval uterine sac length, male and female tail length and morphology, and the length and morphology of the spicules and gubernacula. The occurrence of M. crucis in Spain has, as a result of this study, now also been expanded to a larger area of the southern Iberian Peninsula. Morphological and morphometrical analyses showed that M. canadensis and M. ruehmi are very similar, sharing apomorphic characters. In contrast, M. crucis has plesiomorphic characters. Description, measurements and illustrations are provided for these three species.

Steinernema khuongi n. sp. (Panagrolaimomorpha, Steinernematidae), a new entomopathogenic nematode species from Florida, USA.

In this study, molecular (ribosomal sequence data), morphological and cross-hybridization properties were used to identify a new Steinernema sp. from Florida, USA. Molecular and morphological data provided evidence for placing the novel species into Clade V, or the 'glaseri-group' of Steinernema spp. Within this clade, analysis of sequence data of the rDNA genes, 28S and internal transcribed spacer (ITS), depicted the novel species as a distinctive entity and closely related to S. glaseri and S. cubanum. Additionally, cross-hybridization assays showed that the new species is unable to interbreed with either of the latter two species, reinforcing its uniqueness from a biological species concept standpoint. Key morphological diagnostic characters for S. khuongi n. sp. include the mean morphometric features of the third-stage infective juveniles: total body length (average: 1066 µm), tail length (average: 65 µm), location of the excretory pore (average: 80.5 µm) and the values of c (average: 16.4), D% (average: 60.5), E% (average: 126) and H% (average: 46.6). Additionally, males can be differentiated from S. glaseri and S. cubanum by the values of several ratios: D% (average: 68), E% (average: 323) and SW% (average: 120). The natural distribution of this species in Florida encompasses both natural areas and citrus groves, primarily in shallow groundwater ecoregions designated as 'flatwoods'. The morphological, molecular, phylogenetic and ecological data associated with this nematode support its identity as a new species in the S. glaseri-group.

Characterization of Polish Steinernema silvaticum isolates (Nematoda: Steinernematidae) using morphological and molecular data.

Four strains of entomopathogenic nematodes were isolated with a live trap method in southern Poland. The isolates were identified as Steinernema silvaticum based on morphological, morphometric and molecular data. Infective juveniles of Polish S. silvaticum isolates differ in body length from S. weiseri (951 vs 740 µm, respectively), and in the hyaline tail portion from S. kraussei (48 vs 38%, respectively). First-generation males of S. silvaticum are longer than those of S. kraussei, S. weiseri and S. ichnusae (1829 vs 1400, 1180 and 1341 µm, respectively). Males of S. silvaticum and a sister species S. kraussei can be distinguished by the distance from the anterior end to the nerve ring (142 vs 105 µm), spicule (66 vs 49 µm) and gubernaculum length (45 vs 33 µm), and the presence of a mucron. The analysis of internal transcribed spacer (ITS), D2-D3 and cox1 sequences of the tested nematodes revealed differences of 3-5%, 3% and 12-13%, respectively, from S. kraussei strains. The phylogeny of both nuclear and mitochondrial genes indicated close relationships of the Polish S. silvaticum isolates with S. kraussei, S. oregonense and S. cholashanense. The reproductive isolation of the studied isolates was confirmed by hybridization tests with other European feltiae-kraussei group representatives. This study has supplemented the original description of S. silvaticum with morphological and morphometric characterization of the first-generation males and females. This is also the first molecular study of this species based on a multi-gene approach.

Steinernema pwaniensis n. sp., a new entomopathogenic nematode (Nematoda: Steinernematidae) from Tanzania.

A new species of entomopathogenic nematode, Steinernema pwaniensis n. sp., belonging to the glaseri group, is described from Tanzania. The infective juveniles of S. pwaniensis n. sp. are characterized by a body length of 978 µm (808-1131), distance from anterior end to excretory pore of 86 µm (80-95) and a tail length of 87 µm (75-95). The ratios a, c and E% of S. pwaniensis n. sp. are substantially lower than those of all other African 'glaseri' group members. The first-generation males of S. pwaniensis n. sp. can be distinguished by a large spicule length of 92 µm (80-97) and by the absence of the caudal mucron, while second-generation males possess a short spine-like mucron. First-generation females have a peg-like tail tip bearing three spine-like projections. Second-generation females can be recognized by a slightly protruding vulva and well-developed post-anal swelling. The new species is further characterized by sequences of the internal transcribed spacer (ITS) and partial 28S regions of the ribosomal DNA. Phylogenetic analyses show that S. pwaniensis n. sp. forms a strongly supported monophyletic clade with two other East African species, S. ethiopiense and S. karii.

Morphological and molecular characterisation of an isolate of Steinernema diaprepesi Nguyen & Duncan, 2002 (Rhabditida: Steinernematidae) from Argentina and identification of its bacterial symbiont.

Entomopathogenic nematodes of the families Heterorhabditidae Poinar, 1976 and Steinernematidae Chitwood & Chitwood, 1937 are used for biological control of insect pests. An isolate of Steinernema diaprepesi Nguyen & Duncan, 2002 was recovered from a carrot field in the locality of Santa Rosa de Calchines (Santa Fe Province, Argentina). These nematodes were characterised based on morphological, morphometric and molecular studies. Their symbiotic bacterium was identified as Xenorhabdus doucetiae Tailliez, Pagès, Ginibre & Boemare, 2006 by sequencing the 16S rRNA gene. The isolate of S. diaprepesi studied exhibits some morphometric differences with the original description, especially in the first generation adults. This is the first description of the species in Argentina.

Steinernema jeffreyense n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from South Africa.

During a non-targeted survey for entomopathogenic nematodes in South Africa, a new species of Steinernema was isolated from a soil sample collected from underneath a guava tree, close to the shore at Jeffrey's Bay. The nematode was isolated by means of the insect-baiting technique using last-instar larvae of Galleria mellonella. It is described herein as Steinernema jeffreyense n. sp. The nematode can be separated from other described, closely related species in terms of the morphological and morphometric characteristics of the different life stages, and in terms of the characterization and phylogeny of DNA sequences of the internal transcribed spacer (ITS) rDNA of the 18S gene, and of the D2D3 region of the 28S rDNA gene. The new species is placed molecularly in the arenarium-glaseri-karii-longicaudatum group characterized by the following morphological characters: infective third-stage juvenile with a body length of 926 (784-1043) µm, distance from head to excretory pore of 87 (78-107) µm, tail length of 81 (50-96) µm, with an E% of 109 (86-169), and eight evenly spaced ridges (i.e. nine lines) in the middle of the body. First-generation males have a spicule length of 88 (79-95) µm and gubernaculum length of 57 (51-61) µm. Male mucron is absent in both generations. First-generation females have an asymmetrical protuberance and a short, double-flapped epiptygmata, with both flaps directed to the front. The tail of the first-generation female is shorter than the anal body width, with a mucron on the dorsal tail tip, with D% = 78 (59-99). Cross-hybridization with S. khoisanae, S. tophus and S. innovationi showed the new species to isolate reproductively from the others. The analyses of ITS rDNA and D2D3 sequence of the 18S and 28S rDNA genes support the studied nematode isolate to be a valid new species belonging to the 'glaseri' group (Clade V).

Alloionema similis n. sp., a genetically divergent sibling species of A. appendiculatum Schneider, 1859 (Rhabditida: Alloionematidae) from invasive slugs in California, USA.

A new species of Alloionema Schneider, 1859, A. similis n. sp., and the known species A. appendiculatum Schneider, 1859 were isolated from cadavers of invasive slugs in California. Both species are described based on morphology, morphometrics and molecular data. Alloionema similis n. sp. is morphologically very similar to A. appendiculatum but can be distinguished by a more posterior position of the excretory pore in the Kleinform females and longer tail in the Kleinform males. Substantial differences between the two species are, however, found in both 18S and 28S rDNA sequences. Sequence analysis revealed unambiguous autapomorphies in nucleotide sequence and secondary structure of rRNA genes, separating A. appendiculatum and A. similis n. sp. Molecular phylogenies were inferred from concatenated secondary-structure based multiple sequence alignments of nearly complete 18S and the D1-D3 domains of the 28S rRNA genes. Phylogenetic analyses placed these two species as sister taxa in a monophyletic clade, separately from Neoalloionema tricaudatum Ivanova, Pham Van Luc & Spiridonov, 2016 and N. indicum Nermut, Puza & Mrácek, 2016.

First human case of fatal Halicephalobus gingivalis meningoencephalitis in Australia.

Halicephalobus gingivalis (previously Micronema deletrix) is a free-living nematode known to cause opportunistic infections, mainly in horses. Human infections are very rare, but all cases described to date involved fatal meningoencephalitis. Here we report the first case of H. gingivalis infection in an Australian human patient, confirmed by nematode morphology and sequencing of ribosomal DNA. The implications of this case are discussed, particularly, the need to evaluate real-time PCR as a diagnostic tool.

Adaptive value of a predatory mouth-form in a dimorphic nematode.

Polyphenisms can be adaptations to environments that are heterogeneous in space and time, but to persist they require conditional-specific advantages. The nematode Pristionchus pacificus is a facultative predator that displays an evolutionarily conserved polyphenism of its mouthparts. During development, P. pacificus irreversibly executes either a eurystomatous (Eu) or stenostomatous (St) mouth-form, which differ in the shape and number of movable teeth. The Eu form, which has an additional tooth, is more complex than the St form and is thus more highly derived relative to species lacking teeth. Here, we investigate a putative fitness trade-off for the alternative feeding-structures of P. pacificus. We show that the complex Eu form confers a greater ability to kill prey. When adults were provided with a prey diet, Eu nematodes exhibited greater fitness than St nematodes by several measures, including longevity, offspring survival and fecundity when followed by bacterial feeding. However, the two mouth-forms had similar fecundity when fed ad libitum on bacteria, a condition that would confer benefit on the more rapidly developing St form. Thus, the two forms show conditional fitness advantages in different environments. This study provides, to our knowledge, the first functional context for dimorphism in a model for the genetics of plasticity.

Morphological and molecular characterisation of Steinernema costaricense Uribe-Lorío, Mora & Stock, 2007 (Panagrolaimorpha: Steinernematidae) isolate from Bush Augusta State Park, Missouri, USA.

A new isolate of Steinernema costaricense Uribe-Lorío, Mora & Stock, 2007 (Panagrolaimorpha: Steinernematidae) was discovered from the Bush Augusta State Park, Missouri, USA, and its morphological and molecular examination was carried out. Morphologically, adults of the Missouri isolate are very close to S. costaricense from Costa Rica. Infective juveniles (IJs) from Missouri are characterised by mean body length of 843 µm, mean body width of 33 µm, mean tail length of 80 µm, mean pharynx length of 143 µm, excretory pore at 62 µm from anterior extremity, high cephalic papillae, and lateral field formula 2-6-2 with two central ridges less prominent. They resemble IJs of S. costaricense from Costa Rica in having high cephalic papillae, similar lateral field pattern and pharynx length, but are twice shorter. Based on the nearly complete identity between the sequence of D2-D3 domains of LSU rDNA of the Missouri isolate and those of S. costaricense retrieved from GenBank and the high similarity of their bacterial symbionts, the new isolate was identified as S. costaricense. The phylogenetic affinities among S. costaricense and the species of the "bicornutum" group proposed by the authors of its original description based on LSU rDNA analysis, is debated. In the present study, all three methods of analysis for the ITS region showed that four species of Steinernema from the Americas (S. rarum de Doucet, 1986, S. scarabaei Stock & Koppenhöfer, 2003, S. unicornum Edgington, Buddie, Tymo, France, Merino & Hunt, 2009 and S. costaricense Missouri isolate) formed a weakly supported clade although bootstrap support for the sister-group relationship between the new isolate and S. scarabaei was always high. In phylogenies inferred from D2-D3 LSU rDNA S. costaricense never formed a clade with S. rarum and S. unicornum.

Iberian species of the subgenus Bunobus De Ley, Siddiqi & Boström, 1993 (Nematoda, Rhabditida, Cephalobidae), with description of Pseudacrobeles (Bunobus) rotundilabiatus sp. n. and comments on the subgenus.

Two Iberian species of the subgenus Pseudacrobeles (Bunobus), one new and another known, collected from natural areas are described and illustrated, including morphometric and LM photographs. Pseudacrobeles (Bunobus) rotundilabiatus sp. n. is characterized by a body length of 624-805 µm long in females and 670-714 µm in males, lateral field with three incisures terminating gradually near the phasmid, lip region continuous with the adjacent body, subdorsal and subventral lips rounded, lateral lips reduced, stoma 13-17 µm long, pharyngeal corpus 3.0-4.3 times as long as isthmus, V = 63-74, spermatheca 22-62 µm long, postvulval sac 1.0-2.0 times the body diameter in length, female tail conical elongated (59-83 µm, c = 9.7-11.6, c' = 4.5-6.8) ending in a lanceolate mucro slightly tuberculate proximally, male tail conical (38-40 µm long, c = 10.1-16.8, c' = 3.9), spicules 25 m long, and gubemaculum 14 m long. Pseudacrobeles (Bunobus) pseudolatus is re-described based on type specimens. In addition, an emended diagnosis is provided for the subgenus as well as an updated list of species, a compendium of their morphometrics and a key to their identification.

Description of Quercorhabditis rajouriensis gen. n., sp. n. (Nematoda: Rhabditidae).

Quercorhabditis rajouriensis gen. n., sp. n. is described and illustrated. Distinctive characters include a labial region set off by a constriction and wider than adjoining body, heavily sclerotized cheilostom with arched rhabdions, barely differentiable stegostom, amphidelphic gonads, spicules with a free dorsal arm, and a leptoderan bursa with ten pairs of bursal papillae. The new genus resembles Diploscapteriodes Rahm, 1928 in the shape of cheilostom, presence of amphidelphic gonads, leptoderan bursa and long conoid tail. However, it can be differentiated from the latter genus in the shape of labial region, cheilostomal sclerotization, absence of ridge-like tooth in gymnostom, having spicules with a free dorsal arm, somewhat boat-shaped gubernaculum and in having ten pairs of bursal papillae. The new genus also resembles Curviditis (Dougherty, 1953) Andrássy, 1983, Rhabditella (Cobb, 1929) Chitwood, 1933 and Metarhabditis Tahseen et. al., 2004 in having spicules with free dorsal arm. However, it can be differentiated from these related genera by its heavily cuticularised cheilostom with arched rhabdions and barely differentiable stegostom. The new genus can further be differentiated from Curviditis and Rhabditella in having a well developed bursa and from Metarhabditis by its leptoderan bursa with ten pairs of bursal papillae arranged in 3+4+3 arrangement.

The genera Nothacrobeles Allen & Noffsinger, 1971 and Zeldia Thorne, 1937 (Nematoda: Rhabditida: Cephalobidae) from southern Iran, with description of N. abolafiai sp. n.

A new species of the genus Nothacrobeles Allen & Noffsinger, 1971 is described from a natural area in Kerman Province, Iran. Nothacrobeles abolafiai sp. n. is characterized by its body length (518-655 µm in females), "single" cuticle, lateral field with three incisures, labial probolae 8.5-9.4 µm long, bifurcated and without tines, bearing a minor curvature at the tip, pharyngeal corpus 3.3-4.1 times isthmus length, R(ex) = 25-32, spermatheca 22-30 µm long or 0.8-1.2 times the corresponding body diameter, postuterine sac 15-18 µm long or 0.5-0.7 times the corresponding body diameter, female tail conical with rounded terminus (31-43 µm, c = 11.9-18.1, c' = 1.7-2.4), and phasmid at 38-43% of tail length. In addition, two species of the genus Zeldia Thorne, 1937: Z. punctata (Thorne, 1925) Thorne, 1937 and Z. spannata Waceke, Bumbarger, Mundo-Ocampo, Subbotin & Baldwin, 2005, were recovered. The latter is recorded for the first time from Iran. Description, measurements, illustrations and LM pictures are provided for these three species. Furthermore, comparative morphometrics for the species of Nothacrobeles are given. Molecular analysis based on 28S rDNA (D2-D3 expansion) places this new species of Nothacrobeles in a different clade to other Nothacrobeles species. The results suggest that the genus Nothacrobeles may be a paraphyletic taxon.

Heth longquani sp. n.(Rhigonematomorpha: Hethidae)obligate commensalistic nematode of camballoid millipede (Spirostreptida: Cambalopsidae) from Viet Nam.

A new nematode species, Heth longquani sp. n. (Hethidae, Ransonematoidea, Rhigonematomorpha, Rhabditida) is described from the camballoid millipede, Chonecambala crassicauda from Thanh Ha province, Viet Nam. The morphological features of this new species were studied with brightfield and scanning electron microscopies. Partial sequences of LSU rDNA and Cox1 mtDNA are provided. The phylogeny of the nematodes of the genus Heth Cobb, 1898 is discussed.

Morphological and molecular profiling of an entomopathogenic nematode Steinernema feltiae: Unlocking its biocontrol potential against vegetable insect pests.

A population of entomopathogenic nematodes, belonging to the Feltiae-clade and labelled J13, was discovered in the agricultural soils of the hilly regions of the Union territory of Jammu and Kashmir, India. Based on morphological, morphometric, and molecular analyses, the nematodes were identified as Steinernema feltiae. The J13 nematode isolate was tested in a laboratory assay for its pathogenicity against six major pests of vegetable crops: Pieris brassicae, Plutella xylostella, Helicoverpa armigera, Agrotis iplison, Trichoplusia ni, and Exelastis atomosa. The morphology of the isolated nematode closely matched the original description, except for the adult females, which had prominent epiptygmata instead of the weakly developed, double-flapped epiptygmata described in the original report. Analysis of the internal transcribed spacer and large subunit rRNA data from the J13 nematodes showed 100% similarity to sequences of the type population, indicating that they are conspecific. The virulence assays revealed that the nematode caused 100% mortality in the tested insect pests within 4872 hours, even at the lowest concentration of 50 infective juveniles per insect. The calculated median lethal concentration varied among the pests, with the lowest number of infective juveniles needed to achieve 50% larval killing being 117 for P. xylostella, 181.74 for P. brassicae, 226.35 for H. armigera, and 202.07 for T. ni at 24 hours post-inoculation. These findings suggest that S. feltiae isolated during the present investigation, may be a viable option for the biocontrol of these insect pests in Kashmir valley, India.

Redescription and molecular characterization of Panagrellus ceylonensis (Nematoda, Rhabditida, Panagrolaimidae) from India.

A species of genus Panagrellus was discovered from a wet season form of an oriental common evening brown butterfly Melanitis leda. In this study, a detailed description of Panagrellus ceylonensis is provided including the morphometry, light microscopy and molecular (18S and 28S rDNA genes) studies. Morphological studies on the species agree with original description and characterized by having 12501481m long body in females and 9491305m in males, lateral fields with four longitudinal incisures, lip region continuous and 811 m wide, six offset lips with protruding labial sensilla, neck 124173 m long, excretory pore at the level of basal bulb, vulva post-equatorial (V = 6871), vagina anteriorly orientated with heavily muscled vaginal walls, post-vulval uterine sac 111135 m long or 1.72.6 times as long as the corresponding body diameter, tail conical elongate with an acute terminus in both sexes, spicule 7191 m long, ventrally curved having hooked manubrium and bifurcated lamina tip, lamina ventrally curved with dorsal deflexion at about 60% of spicule length, gubernaculum 2631 m long and well developed. Morphologically, the Indian population of P. ceylonensis does not show a significant difference from the type material of P. ceylonensis in the original description. For molecular studies of this species, the sequence of 18S rDNA is obtained for the first time. Phylogenetic trees based on 18S and 28S rDNA sequences are provided in this study. Additionally, bionomics and global distribution of the species of Panagrellus genus are also discussed. In conclusion, our study provides a comprehensive morphological characterisation and molecular marker sequences of 18S, and 28S genes that can be used to support future taxonomical research on this species and emphasizes the importance of combining molecular data with morphological data to describe the species accurately.

TARANTOBELUS JEFFDANIELSI N. SP. (PANAGROLAIMOMORPHA; PANAGROLAIMIDAE), A NEMATODE PARASITE OF TARANTULAS.

Multiple tarantula deaths for a wholesale breeder were reported in 2018. The breeder noticed white discharge in the oral cavities of the tarantulas. Upon inspection, it was discovered that the white discharge was a large group of nematodes intertwined inside the tarantula's oral cavity. We examined the nematodes and propose a new species, Tarantobelus jeffdanielsi n. sp., in the currently monotypic genus Tarantobelus based on a combination of morphological and morphometrical data and unique nuclear rDNA 28S and 18S sequences. Based on phylogenetic analyses, the previously described Tarantobelus arachnicida was relocated, along with T. jeffdanielsi, into the family Panagrolaimidae. We also provide evidence of the ability of T. jeffdanielsi to parasitize Galleria mellonella larvae and the tarantula Grammostola pulchra. The life span and fecundity of the new species were also assessed, resulting in an 11.2-d average life span, and a total fertility rate of 158 nematodes/adult.