The otter shrews are members of the subfamily Potamogalinae within the family Tenrecidae. No description of the ovaries of any member of this subfamily has been published previously. The lesser hedgehog tenrec, Echinops telfairi, is a member of the subfamily Tenrecinae of the same family and, although its ovaries have not been described, other members of this subfamily have been shown to have ovaries with non-antral follicles. Examination of these two species illustrated that non-antral follicles were characteristic of the ovaries of both species, as was clefting and lobulation of the ovaries. Juvenile otter shrews range from those with only small follicles in the cortex to those with 300- to 400-µm follicles similar to those seen in non-pregnant and pregnant adults. As in other species, most of the growth of the oocyte occurred when follicles had one to two layers of granulosa cells. When larger follicles became atretic in the Nimba otter shrew, hypertrophy of the theca interna produced nodules of glandular interstitial tissue. In the tenrec, the hypertrophying theca interna cells in most large follicles appeared to undergo degeneration. Both species had some follicular fluid in the intercellular spaces between the more peripheral granulosa cells. It is suggested that this fluid could aid in separation of the cumulus from the remaining granulosa at ovulation. The protruding follicles in lobules and absence of a tunica albuginea might also facilitate ovulation of non-antral follicles. Ovaries with a thin-absent tunica albuginea and follicles with small-absent antra are widespread within both the Eulipotyphla and in the Afrosoricida, suggesting that such features may represent a primitive condition in ovarian development. Lobulated and deeply crypted ovaries are found in both groups but are not as common in the Eulipotyphla making inclusion of this feature as primitive more speculative.

Keywords:
Corpora lutea, Non-antral follicles, Ovarian lobulation, Afrotheria
1.
Bedford, J.M., O.B. Mock, S.K. Nagdas, V.P. Winfrey, G.E. Olson (1999) Reproductive features of the eastern mole (Scalopus aquaticus) and star-nosed mole (Condylura cristata). J Reprod Fertil 117: 345–353.
2.
Bedford, J.M., O.B. Mock, S.M. Goodman (2004) Novelties of conception in insectivorous mammals (Lipotyphla), particularly shrews. Biol Rev 79: 891–909.
3.
Bluntschli, H. (1937) Die Frühentwicklung eines Centetinen (Hemicentetes semispinosus Cuv.). Rev Suisse Zool 44: 271–282.
4.
Brambell, F.W.R. (1935) Reproduction in the common shrew (Sorex araneus Linnaeus). I. The oestrous cycle of the female. Phil Trans R Soc Lond Ser B 225: 1–63.
5.
Brambell, F.W.R., K. Hall (1936) Reproduction in the lesser shrew (Sorex minutus Linnaeus). Proc Zool Soc Lond, pp 957–969.
6.
Carter, A.M. (2001) Evolution of the placenta and fetal membranes seen in the light of molecular phylogenetics. Placenta 22: 800–807.
7.
Carter, A.M., T.N. Blankenship, H. Künzle, A.C. Enders (2004) Structure of the definitive placenta of the tenrec, Echinops telfairi. Placenta 25: 218–232.
8.
Deanesly, R. (1934) The reproductive processes of certain mammals. Part VI. The reproductive cycle of the female hedgehog. Phil Trans R Soc Lond Ser B 223: 239–276.
9.
Dryden, G.L. (1969) Reproduction in Suncus murinus. J Reprod Fertil Suppl 6: 377–396.
10.
Guraya, S.S. (1991) Interstitial cells; in Familiari, G., S. Makabe, P.M. Motta (eds): Ultrastructure of the Ovary. Boston, Kluwer Academic Publishers, pp 198–223.
11.
Horst, C.J. van der, J. Gillman (1940) Ovulation and corpus luteum formation in Elephantulus. S Afr J Med Sci 5: 73–91.
12.
Horst, C.J. van der, J. Gillman (1941) The number of eggs and surviving embryos in Elephantulus. Anat Rec 80: 443–452.
13.
Kaneko, T., H. Iida, J.M. Bedford, S. Oda, T. Mori (2003) Mating-induced cumulus-oocyte maturation in the shrew, Suncus murinus. Reprod 126: 817–826.
14.
Kayanja, F.I., J.B. Sale (1973) The ovary of rock hyrax of the genus Procavia. J Reprod Fertil 33: 223–230.
15.
Kress, A. (1984) Ultrastructural studies on oogenesis in the shrew (Crocidura russula): I. The preantral follicle. J Morphol 179: 59–71.
16.
Künzle, H. (1998) Care and breeding of the Madagascan hedgehog tenrec, Echinops telfairi, under laboratory conditions. Der Tierschutzbeauftragte 1/98: 5–12.
17.
Landau, R. (1938) Der ovariale und tubale Abschnitt des Genitaltraktus beim nicht-graviden und beim früh-graviden Hemicentetes-Weibchen. Biomorphosis 1: 228–264.
18.
Mossman, H.W., K.L. Duke (1973) Comparative Morphology of the Mammalian Ovary. Madison, University of Wisconsin Press.
19.
Murphy, W.J., E. Eizirik, S.J. O’Brien, O. Madsen, M. Scally, C.J. Douady, E. Teeling, O.A. Ryder, M.J. Stanhope, W.W. de Jong, M.S. Springer, (2001) Resolution of the early placental mammal radiation using Bayesian phylogenetics. Science 294: 2348–2351.
20.
Nicoll, M.E., P.A. Racey (1985) Follicular development, ovulation, fertilization and fetal development in tenrecs (Tenrec ecaudatus). J Reprod Fertil 74: 47–55.
21.
O’Donoghue, P.N. (1963) Reproduction in the female hyrax (Dendrohyrax arborea ruwenzorii). Proc Zool Soc Lond 141: 207–237.
22.
Pearson, O.P. (1944) Reproduction in the shrew (Blarina brevicauda Say). Am J Anat 75: 39–93.
23.
Perry, J.S. (1953) The reproduction of the African elephant, Loxodonta africana. Phil Trans R Soc Lond Ser B 237: 93–149.
24.
Rubenstein, N.M., G.R. Cunha, Y.Z. Wang, K.L. Campbell, A.J. Conley, K.C. Catania, S.E. Glickman, N.J. Place (2003) Variation in ovarian morphology in four species of New World moles with a peniform clitoris. Reproduction 126: 713–719.
25.
Stanhope, M.J., V.G. Waddell, O. Madsen, W. de Jong, S.B. Hedges, G.C. Cleven, D. Kao, M.S. Springer (1998) Molecular evidence for multiple origins of Insectivora and for a new order of endemic African insectivore mammals. Proc Natl Acad Sci USA 95: 9967–9972.
26.
Strauss, F. (1938a) Die Befruchtung und der Vorgang der Ovulation bei Ericulus aus der Familie der Centetiden. Biomorphosis 1: 281–312.
27.
Strauss, F. (1938b) Die Bildung des Corpus luteum bei Centetiden. Biomorphosis 1: 489–544.
28.
Strauss F. (1950) Ripe follicles without antra and fertilization within the follicle: A normal situation in a mammal. Anat Rec 106: 251–252.
29.
Tripp, H.R.H. (1971) Reproduction in elephant-shrews (Macroscelididae) with special reference to ovulation and implantation. J Reprod Fertil 26: 149–159.
© 2005 S. Karger AG, Basel
2005
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.