spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online January 17, 2007
Journal of Experimental Biology 210, 432-437 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.02673
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Van Look, K. J. W.
Right arrow Articles by Holt, W. V.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Van Look, K. J. W.
Right arrow Articles by Holt, W. V.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Dimorphic sperm and the unlikely route to fertilisation in the yellow seahorse

Katrien J. W. Van Look1,*, Borys Dzyuba2, Alex Cliffe3, Heather J. Koldewey3 and William V. Holt1,*

1 Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
2 Institute for Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of the Ukraine, 23 Pereyaslavskaya Street, Kharkov 310015, Ukraine
3 Zoological Society of London, Regent's Park, London NW1 4RY, UK


Figure 1
View larger version (103K):
[in this window]
[in a new window]

  		Fig. 1. Yellow seahorse spermatozoa illustrating the two types. (A,B,D) Type 1 spermatozoa of different flagellar lengths; (C) Type 2 spermatozoon with the larger head. Scale bar, 13 µm.

 

Figure 2
View larger version (10K):
[in this window]
[in a new window]

  		Fig. 2. Head and flagellar measurements of Types 1 and 2 spermatozoa. (A) Principal components analysis (using sperm head length, width and length:width ratio) showed that the spermatozoa fell distinctly into the two groups (Types 1 and 2) with one outlier, and both sperm head length and width were significantly different (post-hoc ANOVA analyses: length, F1/42=135.4, P<0.001; width, F1/42=434.2, P<0.001, N=44). (B) Sperm heads of Type 1 spermatozoa measured 3.7 µm (median) in length (solid line), whereas sperm heads of Type 2 spermatozoa were significantly longer (dotted line), measuring 13.4 µm (median) in length. (C) Flagella of Type 1 spermatozoa (circles) varied in length between 6.3 and 69.3 µm (49.3 µm median), whereas flagellar lengths of Type 2 spermatozoa (triangles) ranged from 13.5 to 80.4 µm (25.1 µm median). The horizontal line in each group signifies the median value; *P=0.045 (N=44) indicates a significant difference by a Mann–Whitney test (two-tailed).

 

Figure 3
View larger version (12K):
[in this window]
[in a new window]

  		Fig. 3. Mating sequence of a yellow seahorse couple; hand drawn from video sequence. The time is shown above the images and demonstrates the duration when (A) the brood pouch remains opened (PO), (B) when gamete transfer occurs and (C) when the pouch is closed (PC).

 

Figure 4
View larger version (131K):
[in this window]
[in a new window]

  		Fig. 4. Image of a male yellow seahorse showing the exteriorly directed sperm duct, which is located 4.5 mm anterior to the opening of the brood pouch. SDO, sperm duct opening; AF, anal fin; SF, skin folds; PO, pouch opening. Scale bar, 2 mm.

 

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



© The Company of Biologists Ltd 2007