Peripatoides novaezealandiae, (Hutton, 1876) (Hutton, 1876)

Pripnow, Birgit & Ruhberg, Hilke, 2003, Peripatopsidae (Onychophora) from New Zealand - observations on selected morphs of the ‘ Peripatoides novaezealandiae-complex’ in culture: morphological and reproductive aspects, African Invertebrates 44 (1), pp. 103-114 : 105-110

RESULTS

Morphological characteristics of adults

The base colour of all observed Peripatopsidae was a dark bluish grey. However, the different morphs had varying numbers and patterns of orange papillae. All animals examined had a bulge of orange-coloured papillae situated in a latero-ventral position relative to the eyes ( Fig. 2 ). This was considered to be a good characteristic for morphs of the ‘ P. novaezealandiae -complex’. Furthermore, animals from Mohi Bush, Monckton and Woodville Gorge had two orange-coloured ‘ocular papillae’ ( Fig. 2 ), whilst animals from the other three locations lacked these.

The animals investigated had 15 pairs of legs, with three complete sole pads on the ventral part of each leg, and an additional fragmented one, proximal to the others ( Fig. 3 ). Three distal papillae were present on every foot. The shape of the nephropore was hard to differentiate because the animals were moving, but it was apparent that its size varied between animals.

The male genital pores were circular in shape and either orange-coloured or brownish grey with an orange frame ( Fig. 4 ). The female genital pores were circular, swollen, and lipped, and again either orange-coloured or brownish grey. Interestingly, the lateral, orange-coloured anal papillae of the males from all locations studied here were converging ( Fig. 13 ), except for the anal papillae of Woodville Gorge males ( Fig. 14 ).

On the basis of these observations, the six morphs proved to be morphologically distinguishable. A preliminary key was developed that could be extended to include other morphs and could possibly be used for field work.

Preliminary key for six morphs of the ‘ Peripatoides novaezealandiae -complex’

1 Two orange-coloured ‘ocular papillae’ present in a latero-ventral position relative to the eyes ............................................................................................................. 2

– Two ‘ocular papillae’ absent................................................................................. 4

2 Lateral anal papillae of males converging ............................................................ 3

– Papillae not converging ............................................................... Woodville Gorge

3 Female genital pore orange, swollen and lipped, rather long. Nephropore subdivides 3 rd sole pad of foot in half or more ......................................................... Monckton

– Female genital pore brown-grey, swollen and lipped, circular. Nephropore subdivides 3 rd sole pad of foot in half or less........................................ Mohi Bush

4 Nephropore subdivides 3 rd sole pad of foot more than halfway ........................... 5

– Nephropore subdivides 3 rd sole pad halfway (at 5 th pair of legs further than half)…………. ......................................................................... Paengaroa Mataroa

5 Male genital pore orange coloured, circular............................... Boundary Stream

– Male genital pore brown-grey, orange framed, circular .................... Kapiti Island

Data from births

In this study, a total of six females each produced offspring during the observation time. This is remarkable considering the time they had been kept in captivity prior to this study, namely 17 to 24 months, and also considering the relatively short observation period.

Some onychophorans accidentally gave birth to premature hatchlings that did not survive; for example, a female from Kapiti Island had 22 premature hatchlings. Most of the premature hatchlings were not morphologically differentiated. Exceptions were: a blue-whitish premature onychophoran from Monckton ( Fig. 5 ); a premature hatchling from Boundary Stream ( Fig. 6 ), whose slime gland had slipped through a wound in the skin of the animal so that the oral tube—already filled with glue—could be seen; and another premature animal from Boundary Stream, on which an exuvium was seen.

Early stages of embryos from P. novaezealandiae s. str. and from Monckton looked superficially identical, but later stages varied: there was a longitudinal and a semicircular ridge seen on the head, as well as a longitudinal ridge on the body of P. novaezealandiae s. str. embryos, whilst embryos from Monckton lacked these.

Six females gave birth to a total of 68 juveniles during the short investigation period. The reproductive period of the observed morphs during which all juveniles of each female were born was usually one month long, but took place in different months for the different morphs ( Table 2 ). In contrast, the reproductive period of the Paengaroa Mataroa morph was longer, namely three months.

Pigmentation and brightness of the integument in new born animals

All the observed morph offspring were born with pigments, in contrast to the whitecoloured neonates of P. novaezealandiae s. str. ( Tutt 1997; Brosius 1998). The consistent base colour of the morph neonates was a dark bluish grey, except for newborn from Boundary Stream, which had a light white-purple tint, and neonates from Mount Auckland, which had a light brownish beige or brownish blue coloration. All newborn from the different morphs had varying numbers and patterns of orange papillae. Literary sources confirm that coloration of the integument of juveniles becomes stronger during the first two weeks after birth ( Ruhberg 1981).

In this study three stages of pigmentation and coloration of the integument were distinguished in offspring:

• Stage A: neonates shortly after birth: the integument appears wet and always has a silvery sheen ( Fig. 7 ), except for the integument of Mount Auckland juveniles, which has no such sheen. The integument shows varying degrees of pigmentation. The base colour is mainly dark grey or white-purple. The sensory spines of the papillae are exposed like needles ( Fig. 8 ).

• Stage B: the integument is more strongly pigmented, but without lustre. The sensory spines of the papillae are still exposed to some extent. Stage B of the integument was developed at the latest nine days after birth.The change to stage C is hard to determine.

• Stage C: the integument is fully pigmented and without lustre. The papillae resemble those of adults ( Fig. 9 ).

The time to reach the fully developed stage C differed markedly between the morphs, which might be one method of distinguishing them. Stage C was reached after less than 25 days after birth by juveniles from Monckton and Woodville Gorge, up to 50 days after birth by juveniles from Boundary Stream, and more than 50 days after birth by juveniles from the other three locations, Ngapaerera, Paengaroa Mataroa, and Mount Auckland.

Anal cone and genital pore in two and five month old juveniles

There have been no previous reports describing the shape of anal cones and genital openings or the development of these structures in juveniles. Examination of these features in live animals is difficult because of the risk that they might die as a consequence of disturbance. Therefore, several offspring from the same location were examined for very brief periods using a stereo-microscope. Only juveniles that survived five months after birth were included in this investigation ( Table 3 ).

Two months after birth gender determination was impossible for onychophorans from Boundary Stream (for details of ventral anal cone, see Fig. 10 ). In addition, gender was not determined for two juveniles from Woodville Gorge after two months ( Fig. 12 ), but they were found to be females after five months. However, gender determination was possible for all other observed juveniles two months after birth. Nonetheless, their genital pores were more differentiated five months after birth than earlier.

An extraordinary sex ratio was that of morphs from Boundary Stream and Paengaroa Mataroa. In total, the female from Boundary Stream produced no males but 13 females ( Fig. 11 ), and the female from Paengaroa Mataroa produced no females but five males ( Fig. 13 ). The female from Woodville Gorge produced altogether 10 male ( Fig. 14 ) and seven female ( Fig. 15 ) offspring. The only surviving offspring from Monckton was male.

Genital openings of undifferentiated Boundary Stream ( Fig. 10 ) and Woodville Gorge ( Fig. 12 ) juveniles (two months old) were either light grey (Boundary Stream) or bluish grey (Woodville Gorge). They were framed by either two grey pads (Boundary Stream) or one pad (Woodville Gorge). Towards the posterior end of the body a zone of orangecoloured papillae could be distinguished in juveniles of both of these morphs (Boundary Stream and Woodville Gorge).

Five month old females from Boundary Stream ( Fig. 11 ) and Woodville Gorge ( Fig. 15 ) had orange genital openings, and areas of orange and grey papillae. The genital pore was framed by either one (Boundary Stream) or two (Woodville Gorge) grey pads. Genital pores of five month old Paengaroa Mataroa ( Fig. 13 ) and Woodville Gorge males ( Fig. 14 ) were light grey. They had two pads caudally as well as a zone of orange papillae, in rows in the case of Paengaroa Mataroa. As in male adults of this morph, the lateral orange anal papillae were either converging (Paengaroa Mataroa) ( Fig. 13 ) or not converging (Woodville Gorge) ( Fig. 14 ).

During the investigation of juveniles with the stereo-microscope many of them deposited drops of urine at the nephropore of the fourth and fifth pair of legs. This was also observed during weight recordings.

Figures

Fig. 2. Head of Monckton male, lateral view (20 x).

Figs 3–5. Diagram, micrograph and photograph of selected morphs. 3. Schematic sketch of Mohi Bush male: fifth leg, ventral view (Scale bar = 163 m). 4. SEM micrograph of genital pore: Monckton male (Fig. rotated approx. 45˚). 5. Monckton: premature hatchling (25 x).

Figs 10–13. Sketches of posterior ventral body surface. 10. Juvenile from Boundary stream, 2 months, genital area and papillae of anal cone still undifferntiated (30 x). 11. Juvenile from Boundary Stream, 5 months, female (30 x). 12. Juvenile from Woodville Gorge, 2 months, genital area and papillae of anal cone still undifferentiated (30 x). 13. Juvenile from Paengora Mataroa, 2 months, male (30 x).

Figs 14–15. Sketches of posterior ventral body surface. 14. Juvenile from Woodville Gorge, 5 months, male (30 x). 15. Juvenile from Woodville Gorge, 5 months, female (30 x).

Figs 6–9. Selected hatchlings and juveniles. 6. Boundary Stream: premature hatchling with slime gland (25 x). 7. Juvenile from Ngapaerera: stage A (7 x). 8. Juvenile from Boundary Stream: stage A (7 x). 9. Juvenile from Monckton: stage C (10 x).

Tables

TABLE 2. Number of juveniles born during this study from females of different locations.

Location	Boundary Stream	Kapiti Island	Mohi Bush	Monckton	Paengaroa Mataroa	Woodville Gorge	Mount Ngapaerera Auckland
Number of
females	1	–	–	1	1	1	1	1
Number of
juveniles	13	–	–	3	8	17	12	15
Timing of
birth
periods	Feb.–Mar.	–	–	Apr.–May	Jul.–Sept.	Feb.–Mar.	May–Jun.	May–Jun.
Duration
of birth
periods	1 month	–	–	1 month	3 months	1 month	1 month	1 month

TABLE 2.

Number of juveniles born during this study from females of different locations.

TABLE 3. Gender determination of juvenile morphs from different locations.

Locations	Number of juveniles observed for gender	Gender determination after 2 months females males		Gender determination after 5 months females males
Boundary Stream	13	–	–	13	–
Monckton	1	–	1	–
Paengaroa Mataroa	5	–	5	–	–
Woodville Gorge	17	5	10	2	–

TABLE 3. Gender determination of juvenile morphs from different locations.