Peter R. Morrison.
Parturition in Peripatus.
Psyche 53(1-2):1-3, 1946.

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PSYCHE
PARTURITION IN PERIPATUS
Biological Laboratories, Harvard University, Cambridge, Massachusetts
Despite numerous and extensive studies on the habits and life history of various of the Onych~phora,~-~ with the exception of Steel
who reported no details, there appear to have been no observations on parturition in this group. This is perhaps not surprising when one considers their retiring nature and strong negatively phototropic reactions which make difficult even the observation of the more ordinary activities such as ecdysis and feeding. Since their viviparous mode of reproduction is one of their more unusual characteristics, observations on parturition are of interest.
These peripatus were secured on Barro Colorado Island, C. Z., through the great kindness of Mr. James Zetek. They were taken in September of 1941 and these observations were made in Cambridge about a month later. During the interim they were kept in moist forest debris but were not given addi- tional suitable food. The large female in which successful par- turition was observed had an extended length of 60 mm, had 33 pairs of legs and was uniformly colored a rich red-brown. It was Epiperipatus brusiliensis vaguns BruesI6 for which the Island is the type locality.
Twenty three days previously she
had given birth to a single young and another was found just before these observations were made.
Wanton, S. M., Ann. Mag. Nat. Hist., (11) 1:SlS-528 (1938). ' Holliday, R. A., Ann. Natal Mus., 10: 237-244 (1942). Andrews, E. A., Quart. Rev. Biol., 8:lSS-163 (1933). 'Steel. T.. Proc. Linnean Soc. New South Wales. 21:94-104 (1896). ' ~ed~kick, A., Quart. Jour. Micr. Sci., 28:431-493 (1887). ' Brues, C. T., Psyche, 32: 159-165 (1925).



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2 Psyche [March- June
When first noticed only 4 mm of the young was visible but by 15 minutes later, 16 mm or more than half of its length had emerged. Another 15 minutes sufficed for the young to com- pletely free itself so that the entire process must have required little more than half an hour. During this time the female held TABLE 1
..............
8:45~.~. 4mm. free
9:OO ............ 16 " "
9:05 ............. 20 " ('
9:lO ............ 24 " "
9:15 ............. Completelyfree
9:17 ............ White mass extruded
9:45 .............. Mass consumed by young the posterior part of her body (that portion bearing the last 5 pairs of legs) raised at an angle of about 60'. She made no move- ments and no contraction or peristaltic action could be seen. The young on the other hand made active efforts to free itself and apparently maintained a constant tension. The portion of its body which had just emerged (6 mm) was very pale, almost white, and was separated from the rest of the body by a dark band (2 mm) . These bands presumably represented ex- tended and contracted regions respectively. The young was closely followed by a drop of white, cloudy, viscous liquid 1.5 to 2.0 mm in diameter. Manton (loc. cit.) states that in Peripa- toides the cast egg membrane, the peritrophic membrane and the cast integument are evacuated after birth but no structure could be seen in this material. The mass was completely eaten by the young in half an hour.
After parturition the mother
showed no interest in the young even casually walking over it. However, neither did she attempt to harm or consume the young, either at this time or on succeeding days although she had been without food for the better part of a month. With a length of half that of the mother the young appear large but their combined weight was less than 15 per cent of hers. In contrast to the adult which was uniformly colored a rich red-brown, the young showed a lighter red-violet-brown with pinker head, legs and undersides This difference in color appears to be characteristic in peripatus.



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19461 Parturition in Peripatus 3
An unsuccessful parturition was observed in a smaller indi- vidual of another specie^.^ Here the young was apparently in- jured and died when only one fourth extruded. In this case strong contractions of the posterior portion of the female's body were observed but she was unable to complete parturition more TABLE 2
LENGTH IN MM.
Pairs Weight
of legs in mg. Contracted Extended
Adult
33 786 50 60
Young # 1
33 48 23 33
Young # 2
3 4 5 4 24 3 1
than half way. Forceps delivery was resorted to in an attempt to save the adult, but unsuccessfully since she died about 12 hours later. It may well be that this failure was occasioned by placing the animal under observation since the smaller species was characteristically much more active and upset when re- moved from shelter. The larger species was much more tolerant of observation and for this reason may be particularly suitable material for studies on this group.
This animal, also from Barro Colorado Island, was one of several Oroperi- patus cord. It had a contracted length of 36 mm and was a light chocolate color with a lighter under side and with darker legs and a dark, median dorsal stripe 0.3 mm wide.




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