Hammerschmidtiella keeneyi, Carreno, Ramon A., 2017

Carreno, Ramon A., 2017, New species of Hammerschmidtiella Chitwood, 1932, and Blattophila Cobb, 1920, and new geographical records for Severianoia annamensis Van Luc & Spiridonov, 1993 (Nematoda: Oxyurida: Thelastomatoidea) from Cockroaches (Insecta: Blattaria) in Ohio and Florida, U. S. A., Zootaxa 4226 (3), pp. 429-441 : 430-433

Hammerschmidtiella keeneyi n.sp.

( Figs. 1 A–F, 3A–D; Table 1 )

Description (based on 16 males, 41 females). Male: Body with thin anterior half, prominent expansion of midbody, and slender posterior and tail region ( Fig. 1 E). Narrow lateral alae present, extending from corpus to precloacal region. Esophagus with base of corpus slightly expanded, thin isthmus, and elongate bulb. Nerve ring posterior to base of corpus. Excretory pore posterior to esophagus. Three pairs of caudal papillae present, including one pair subventral precloacal, one pair lateral postcloacal papillae, both pairs slightly raised from the body surface, and one pair on base of tail appendage ( Figs. 1 F, 3B). Phasmids situated on cuticular expansion immediately posterior to cloaca. Spicule present. Gubernaculum absent. Tail ending long, filiform.

Female: Oral opening surrounded by eight oblong-quadrate myolabia ( Figs 1 C, 3C, D). Inner lining of oral opening (cheilostom) with three small projections of tridentate structures, one on each lobe of the esophagus ( Fig. 3 D). Amphids semicircular with rounded portion facing outward. Oral annule small, circular, followed by 5–9 prominent cuticular annules ( Fig. 3 A); subsequent cuticular annules less distinct. Narrow lateral alae present, arising from a point immediately anterior to the vulva and extending to anus. Esophageal corpus with slight rounded expansion at distal end and with wide base. Nerve ring anterior to broad portion of corpus ( Fig. 1 B). Isthmus cylindrical. Basal bulb spherical with valvular apparatus. Excretory pore posterior to esophageal bulb. Intestine slightly dilated at anterior end, but not forming a prominent cardia. Vulva located at anterior third of body, consisting of a crescent-shaped opening with a slight, smooth cuticular extension; vagina directed posteriorly ( Fig. 1 A). Uterus branches into two ovaries usually terminating in anterior portion of body. Didelphic, prodelphic. Rectal glands present. Tail subulate ( Fig. 1 D). Eggs long, oval, slightly flattened on one side. Measurements in Table 1 .

Character Holotype Paratype females Allotype male Paratype males

female (n=40) (n=15) Taxonomic summary

Type host: Diploptera punctata (Eschscholtz, 1822) ( Blattaria : Blaberidae )

Type locality: captive host colony, insectary, Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio, U.S.A.

Site of infection: hindgut

Prevalence: 82%; mean intensity = 2.8; ratio of males to females = 1:1.69.

Specimens deposited: holotype female, HWML 99914; allotype male HWML 99915; paratype two males HWML 99916; paratypes, 12 females HWML 99917.

Voucher DNA sequences: 18S small subunit ribosomal RNA gene, partial sequence GenBank accession number KX752429 . The 28S ribosomal RNA gene, partial sequence, GenBank accession number KX752430 .

Etymology. This species is named in honor of George Keeney, entomologist, director of the Ohio State University insectary, and valued colleague.

Remarks. Hammerschmidtiella keeneyi n. sp. differs from the type species, H. diesingi (Hammerschmidt, 1838) Chitwood, 1932 , in having several smaller body proportions such as male body length, distance of nerve ring to anterior end, esophageal length, corpus length, and corpus width, spicule length, and tail length (males), and tail length and De Man ratio b in females (see Chitwood, 1932, Lee, 1958, Shah, 2007, and Blanco et al., 2012, for descriptions of H. diesingi ). There is slight overlap in reported female tail length ( Blanco et al., 2012). However, the measurement for H. keeneyi n. sp. (325–535 µm, mean = 410 µm vs 479.4–1132.2 µm, mean = 871.6 µm provided for H. diesingi by Blanco et al., 2012) clearly shows a longer tail length for H. diesingi . Furthermore, the female tail of H. keeneyi n.sp. is not filiform as in H. diesingi and De Man ratio c (body length/tail length) is higher in H. keeneyi n. sp. (range 4–7 vs. 2.6–4 in Blanco et al., 2012). Similarly, ratio b (body length/esophageal length) is smaller (range 6–8 vs. 9.5–16) and does not overlap with that of H. diesingi . Although there is slight overlap in male length, the males of H. keeneyi n. sp. are generally smaller than those of H. diesingi (mean length 436 µm vs. 701 µm) and have a shorter tail length (mean 59 µm vs. 101.3 µm) and esophageal length (mean 90 µm vs. 124.7 µm). Hammerschmidtiella basiri Singh & Kaur, 1988 also has females with longer tails (900–1000 µm) and differs in having the excretory pore anterior to the esophageal bulb rather than posterior to the esophagus ( Singh & Kaur, 1988). Cuticular plates covering the vulva in H. basiri are absent in H. keeneyi n. sp. Interestingly, tooth-like projections similar to those observed for H. keeneyi n. sp. were noted for H. basiri but not illustrated ( Singh & Kaur, 1988). Hammerschmidtiella aspiculus Biswas & Chakravarty, 1963 also included mention of three tooth-like projections in the mouth cavity. However, this species also has a longer female tail (920–960 µm), an excretory pore situated at the level of the esophagus, and smaller eggs (length 74–78 µm vs. 77–98 µm). Male caudal structures were not described in H. aspiculus ( Biswas and Chakravarty, 1963) . Hammerschmidtiella acreana Kloss, 1966 has a shorter female tail whose reported length (482–567 µm) slightly overlaps with that of H. keeneyi n. sp. However, eggs of H. acreana are smaller (length 75–78 µm) and male proportions (body length 590–710 µm; esophagus length 107–117 µm; tail 78–135 µm) are larger than in H. keeneyi n. sp. ( Kloss, 1966).

Hammerschmidtiella indicus Singh & Malti, 2003 has a longer female tail (960–980 µm) and much smaller eggs (length 55–56 µm). Both sexes in this species lack lateral alae. In Hammerschmidtiella mackenziei ( Zervos, 1987) Adamson & Van Waerebeke, 1992 both female (250–290 µm) and male (28 µm) tail lengths are shorter than in H. keeneyi n. sp., male body shape does not have a mid-body expansion, and the caudal region has four pairs of caudal papillae rather than three ( Zervos, 1987). Female tail lengths of Hammerschmidtiella manohari Rao, 1958 (780 µm) and Hammerschmidtiella singhi Rao & Rao, 1965 (658 µm) are longer than that of H. keeneyi n. sp., and males are longer (830 µm for H. singhi , 810–960 µm for H. manohari ). In addition, the males of both H. manohari and H. singhi are slenderer in shape. Hammerschmidtiella keeneyi n. sp. differs from Hammerschmidtiella andersoni Adamson & Nasher, 1987 in lacking a gubernaculum, having a wide mid-body region in males, and in having a shorter female tail (tail length for H. andersoni 579–679 µm). Hammerschmidtiella andersoni was reported from a diplopod in Saudi Arabia ( Adamson & Nasher, 1987).

Hammerschmidtiella cristata Spiridonov, 1984 is distinguished from other species of the genus in having a comb-like structure on the anterior end of the cloaca lip of the male, as observed from a recent redescription of the species from the cockroach Gromphadorhina portentosa (Schaum, 1853) by Guzeeva & Spiridonov (2009). This structure was not observed on males of H. keeneyi n. sp. The tail of H. cristata females is filiform and there is only slight overlap with the longer length range reported for H. cristata (450–660 µm). In Hammerschmidtiella poinari ( Gupta & Kaur, 1978) Adamson & Van Waerebeke, 1992 , the tail length, estimated to be approximately 400 µm based on the illustration of the female tail, falls within the range of that of H. keeneyi n. sp. ( Gupta & Kaur, 1978). However, in H. poinari the vulva is in the mid-region of the body rather than in the anterior third, and the excretory pore is closer to the esophageal bulb.

Hammerschmidtiella keeneyi n. sp. resembles Hammerschmidtiella neyrai Serrano Sanchez, 1945 . The shorter female tail length of H. neyrai (400 µm) falls within the range of H. keeneyi n. sp., and other female body proportions are consistent with the description of H. neyrai ( Serrano Sánchez, 1947) . However, female body length is slightly greater in H. neyrai (2800 µm, no range available, vs 1733–2750 in H. keeneyi n. sp.), egg length is shorter in H. neyrai (78 µm), and male body length (1270 µm), width (80 µm), esophagus (146 µm), and spicule length (28 µm) are greater. Lateral alae are absent in H. neyrai . Hammerschmidtiella hochi Jex, Schneider, Rose, & Cribb, 2005 differs in lacking lateral alae and having the female excretory pore at the level of the bulb, and in having ovoid, pear-shaped eggs.

Figures

FIGURE 1. Hammerschmidtiella keeneyi n. sp. A. Female whole worm. B. Female anterior end. C. Female, en face. D. Female tail, lateral. E. Male, whole worm, lateral. F. Male caudal end, ventral.

FIGURE 3. Scanning electron micrographs. Hammerschmidtiella keeneyi n. sp. A. Female anterior end, lateral. B. Male, tail region, ventral. C, D. En face, female. Blattophila peregrinata n. sp. E. Female, en face. F. Male, lateral view showing lateral alae. G. Eggs in utero. H. Egg showing operculum.

Tables

TABLE 1. Morphometric measurements (in micrometers) for Hammerschmidtiella keeneyi n. sp. The mean and standard deviation are followed by range for paratype measurements.

Body length	2225	2214 ± 224 (1733–2750)	419	436 ± 70 (335–573)
Maximum width	200	222 ±34 (164–300)	49	47 ± 10 (30–69)
Buccal cavity (length)	13	13 ± 3 (8–9)	-	3
Oral annule length	6	6 ± 2 (4–9)	-	-
Oral annule width	23	24 ± 2 (20–26)	-	-
Second annule length	18	16 ± 2 (13–18)	-	-
Second annule width	34	35 ± 3 (23–39)	-	-
Nerve ring	98	103 ± 8 (90–120)	64	52 ± 9 (41–64)
Excretory pore	Not observed	422 ± 12 (410–438)	Not observed	132.5
Distance from base of esophagus to excretory pore	105	98 ± 25 (78–130)	Not observed	32
Esophagus	304	307 ± 20 (262–350)	87	90 ± 7 (77–100)
Corpus length	193	192 ± 15 (158–230)	47	47 ± 4 (43–50)
Corpus maximum width	70	66 ± 5 (56–74)	8	7 ± 1 (7–8)
Width of anterior expansion of corpus	21	23 ± 1 (20–25)	-	-
Isthmus length	48	45 ± 8 (30–60)	26	26
Bulb length	65	71 ± 8 (57–96)	14	15 ± 1 (13–17)
Bulb width	87.5	84 ± 8 (71–105)	11	14 ± 2 (11–15)
Vulva from anterior end	640	669 ± 66 (570–800)	-	-
Vulva from posterior end	1585	1568 ± 150 (1300–1950)	-	-
Vagina length	155	166 ± 15 (155–176)	-	-
Tail length	505	410 ± 57 (325–535)	54	59 ± 6 (45–70)
Egg length	83–90 (n=4)	87 ± 5 (77–98)	-	-
Egg width	30–35 (n=4)	30 ± 3 (25–38)	-	-
a	11	10 ± 2 (7–14)	8.55	10 ± 2 (8–16)
b	7	7 ± 1 (6–8)	4.82	5 ± 1 (4–6)
c	4	5 ± 1 (4–7)	7.76	8 ± 1 (5–9)
V	29	30 ± 2 (26–32)	-	-
Spicule length	-	-	22	21 ± 3 (17–27)