Vol. 29 (2009), No. 10

MI ESOTA HERPETOLOGICAL SOCIETY NEWSLETTER

Oviparity and Viviparity in Reptiles by Heather Clayton .. pgs 3-7 Feeding your Corn snake by Christina Danathar .. pgs 8 & 9 Update from Joe Wasilewski! page 9

October 2009

Volume 29

Number 10

MRS Board of Directors

Minnesota Herpetological Society

President Jennifer Hensley Starbrst72@mns.com

763.862.8966

October 2009

Vice President David Dewitt Ddewitt777@comcast.net

651.983.8272

MHS Voice Mail: 612.624.7065

Group Email: HTTP://WWW.GROUPS.YAHOO.COM/GROUP/ MNHERPSOC

The purpose of the Minnesota Herpetological Society is to: 763.593.5414

•

Treasurer Nancy Haig nanchaig@citilink.com

763.434.8684

Newsletter Editor Kathy Claugherty iwannaiguana@gmail.com

651.771.2267

.. ..

Further the education of the membership and the general public in care and captive propagation of reptiles and amphibians; Educate the members and the general public in the ecological role of reptiles and amphibians; Promote the study and conservation of reptiles and amphibians.

The Minnesota Herpetological Society is a non-profit, tax-exempt organization.

Membership is open to all individuals with an interest in amphibians and reptiles.

The Minnesota Herpetological Society Newsletter is published monthly to provide its members with information concerning the society's activities and a media for exchanging information, opinions and resources.

Members at Large Heather Clayton heethuh@netzero.com Jeff LeClere Reptilia74@aol.com

Number 10

MHS Web Page: HTTP://WWW.MNHERPSOC .ORG

Recording Sectretary Jenna Rypka-Hauer Justna_na@yahoo.com Membership Secretary Ellen Heck Inheck@msn.com

Volume 29

651.488.6388

Chris Smith Chris.smith.mhs@gmail.com Jared Rypka-Hauer jared@web-relevant.com

General Meetings are held at Borlaug Hall, Room 335 on the st. Paul Campus of the University of Minnesota on the first Friday of each month (unless there is a holiday ~onflict). :roe .meetJng· starts.~t.7 :OOjdm.andlasts,abooUf:lreehours., Please check the website for changes in schedules or cancellations.

Submissions to the Newsletter Ads or Notices must be submitted no later than the night of the General Meeting to be included in the next issue. Longer articles will be printed as time and space allows and should be in electronic file format if possible.

See inside back cover for ad rates.

Committees Adoption Chair Sarah Richard realsarah@aol.com

612.781.9544

Education Chair Jan Larson Jan.skunkhollow@juno.com

507.263.4391

Web Master Anke Reinders theMHSwebmaster@yahoo.com Library Carmelita Pfar

Submissions may be sent to: The Minnesota Herpetological Society Attn: Newsletter Editor Bell Museum of Natural History 10 Church St. SE. Minneapolis, MN 55455.0104 Please send email toiwannaiguana@gmail.com

© Copyright Minnesota Herpetological Society 2009. Contents may be reproduced for non-profit use provided that all material is reproduced without change and proper credit is given authors and the MHS Newsletter citing; volume, number, and date.

Cover Photo: Cover photo: Izzy lays her eggs. Submitted by Kathy Claugherty

Snake Bite Emergency Hennepin Regional Poison Center 800.222.1222

Newsletter of the Minnesota Herpetological Society October 2009 Volume 29 Number 10

IS mont am p ease to present a researc paper written your very own member, Heather Clayton. Contributions from MHS members, whether it's poetry, art, survey's, research papers, and even submitted articles are all what makes our newsletter great! the editor

Hello! I wTote this research paper for school last senle8te1', and I thought I 'would share it as the subject ll1atter \vas so interesting. A couple of disclaimers, though ...

This paper was written to get 50 extra credit points for a Biology class I had last semester. It is not meant to be on the saIne level as a scholarly journal, as I used scholarly jou111als for some of my references. So please don't consider this a bona tide reference doculnent. I mean it to be sort of an overview/introduction to the subject. But if you are interested in learning n10re about this subject (or checking my work), please feel free to use the reference list at the end to look more detailed information up. The studies that were perfonned are truly awesome.

I do want to apologize for the poor -method of citing my sources. The professor I wrote this for was not picky about citing methods, so I didn)t stress nlyself over it.

Also, if anyone knovvs about this topic and sees a mistake on my part, or SOlne tidbit you 'could-add to increase my;knowledge on the subject, please tl11me in.

Thanks and I hope you enjoy the fruits of my labor! I got an "A" on the paper, so I guess it is worth the work!

-Heather Clayton

Oviparity and Viviparity in Reptiles

Evolution of Live Birth Heather Clayton

3

Newsletter of the Minnesota Herpetological Society

October 2009 Volume 29 Number 10

Most people think of reptiles as animals that reproduce and lay shelled eggs (oviparity). There are species, however, which give birth to live offspring (viviparity), and those vvho retain yolked eggs until delivery and then give live birth (ovoviviparity).

For clarity, I will refer to ovoviviparity and viviparity collectively as viviparity. The differences between the two are slight regarding the shell membrane, which is the focus of this paper. Among the herpetological community they路 are virtually synonymous.

The evolution of viviparity in reptiles is a conlplicatedmatter. There seem to be very few (if any) traceable paths. of evolution among the various lines over tinle. This Inethod of birth, \vherelive offspring are born, is 110t nearly as common in reptiles as is oviparity. This paper will focus on the development of a shell membrane sac in viviparous species from the eggshell in oviparous species. I would like to start with the processes involved in creating an egg and "sac" which 110lds the offspring~From there I

win try to sununarize \vhat we know about how viviparity specifically evolved in reptiles.

Hopeful1yfl'onl there I can COlne up with SOlne ideas on how to leanl more about ho\v this form of birth came to be among these creatures, who you would not expect to have this ability.

In oviparous reptiles, the eggshell is lnade of two layers. The outer layer is mineral in nature and consists of calcium carbonate (there are exceptions to this as in

cal.cite eggshells in. crocodilians), which is placed on. the egg in "plaques," in no particular order or pattern. The lay-out, however, may hint at the organization of the protein layer underneath. The organic hmer layer is called the shell menlbrane. It is made from multiple layers of protein fibers which vary in size, spacing, and orientation going from the imier to the outer aspect of themernbrane. The eggshell and shell membrane are secreted by the oviduct, leading with the membrane component and followed by the mineralized shell co.mponent. This generally involves ce.lls with proteins whose extracellular matrix holds others of its kind to form the membrane, and those with proteins on the extracellular matrix that attract Calcium to bind to the fibers.

Shell

genesis does not occur until after fertilization so sperm penetration can occur. I could not fmd any data on which genes and gene products contribute to the creation of these

4

Newsletter of the Minnesota Herpetological Society October 2009 Volume 29

Number 10

some shnilarities do exist. Studies have sho'wn that viviparity in reptiles evolved through gradually longer periods of egg retention. Reduction of the thickness of shell layers increases gas and fluid exchange, making maintaining the health of the embryo possible.

Eventually the shell disappeared conlpletely in some species, allowing for l11axinlum. gas and fluid exchange. The prolonged release of progesterone after ovulation represses uterine contractions, so the eggs are not released.. It has been found that there are Inany interm.ediate lengths of time that the eggs are retained. This seems to be dependent on the mother's ability to support the eggs long ieon. An example is Liochlorophis (snake) that lays its eggs only a. few days to a couple of weeks before hatching, and Chan1aeleo (lizard) lays its eggs \vhenthe enlbryo is just entering gastrulation. This is thought to be evidence for the slow evolutionary path to viviparity. (Andrews)(Pough)(Shlne) Inside the developing embryo within the egg (or sac) you have the typical structures needed for en1.bryonic developnlcnt. These include extraelnbryonic membranes like the yolk sac and allantois (fonned from endodernl and splanchnic m.esoderm}, the amnion and chorion (fonned fron1 ectoderm and sOlnatic mesoderm).

The Inesoderm, endodernl, and ectodcnn are the three tissue layers fornled in the embryo upon gastrulation. The respiratory Inembrane is formed from the chorion and allantois.

There is albumen as well, for shock absorption. These structures are generally the sarn.e in both ovi-and viviparous reptiles; however there are exceptions. Most viviparous reptiles are lecithotrophic, so their embryos completely rely on the yolk for nutrition. In SOlne species, ho\-vever, a placenta is formed that is "convergent with the mrunlnalian placenta." I looked for comparisons on how the mammalian placenta forms vs. the reptilian, and could not really find anything. My best guess is that it is a sitnilar process.

(Kardong) The big question is, "Why the diflerence?" Viviparity does have its costs, both to the lnother and the offspring. One of which is that it Ihnits the number of clutches a felnale can produce in one breeding season. Generally clutch size is reduced路in路animals with this reproductive trait in order to accommodate for the growth of the offspring inside the nl0ther. As the gravid (pregnant) female gets larger, heavier, and less capable of quick movement, she becon1es reliant 011 the resources near her, as she will be required to find a safe comfortable den. This will help her avoid predation, but it restricts her

5

Newsletter of the Minnestoa Herpetological Society

October 2009 Volume 29

Number 10

ill.ovenlents which can be a problem if resources and good options for thennoregulation are not near. Studies have also shovm that prolonged periods of egg retention in intemlediate species (those who retain their eggs much longer than "nonnal" but still lay a shelled egg) results in offspring\vho are shol1erin body length and that require longer periods of basking tin1e. This increased exposure and smaller size increases the risk of predation on the offspring. (Pough)(Qual1s) So with all these costs, vvhy did viviparity evolve in the first place? What was the selective pressure?

It appears that the trait of viviparity in reptiles originally evolved primarily in species whose ancestors evolved in cooler temperatures and higher climates. This seems to be the strongest selective pressure that was present at the tilne nla11Y these species developed, although viviparity evolved several times. (Discussion to follow.) The primary benefits are that a gravid female who is thermoregulating is able to keep her enlbryos consistently warmer than nature can for those eggs developing in the ground.

This allows the offspring to develop faster than e.nlbryos growing in eggs in the ground..

This means the babies are born earlier than their "cousins" hatch. Experilnents have shown, based on manipulating the embryos ofLerista lizards (skink), that eggs laid in the ground may take up to 50% longer to hatch than embryos housed in the mother. An earlier birth means several things for the offspring. For one, there are no eggs in the ground for predators to find. So if the mother is healthy and doesn't get killed, her offspring should survive to birth. An eadier birth also means there is nl0re time for the juveniles to find food and grow before the cool season. Environmental factors also pose a risk, such as fluctuating moisture levels leading to desiccation or drowning.

(Renlember not all reptile eggshells ate calcium carbonate and may "breathe" more than you might expect.) In extreme cases, the process of viviparity may allow some species to survive in clilnates where other, oviparous species m.ay not. (Pough)(Qualls)TIlis fits quite nicely,except that there are currently viviparous species in. tropical climates, and egg-laying species in cooler climates. For example, the egg-laying green anaconda and. live-bearing boa constrictor both live in tropical South America. The egg-laying bull snake and live-bearing garter snake both live in temperate Minnesota. My guess is that viviparity evolved in some species during a tinle when the climate would have been

6

Newsletter of the Minnesota Herpetological Society

October 2009

Volume 29

Number 10

10,000 years ago. They remind me of Darwin's fine-hes, who proved that evolution Gall essentially happen in a single generation depending on environmental faGtors.

(Brooker) (Blackburn)(Andrews)(Qualls)(Tinkle) Most of what I found indicates that the hypothesis about viviparity evolving in reptiles being related to the clhnate during the evolution of reptiles thelnselves is generally accepted, and accepted as a n10re recent event. It was tough finding any definitive answers for 'why some species developed viviparity and others did not.

Some experiments one could try in order to develop some answers are:

1. Incubating experinlel1ts involving 111anipulation of environmental factors and traGk affects onemhryos/offspring.

2. Sequence the genes for tnultiple families of reptiles and look for homologies, differences, etc. This nlay have to wait until we can identify the genes involved and know \vhich does what part ....

3. Manipulate the e-liulate in breeder anhnals. Can the

~'switch"

for egg-laying genes

be turned back on with a long enough period ofclimate/environUlental pressure?

References: Vertebrates: C0111parative Anatolny, Function. Evolution Kenneth V. Ka,rdong, 2006 Herpetology Pough, Andrews, Cadle, Crump, Suvitzky, 'Wells, 2001 "Evolution of Viviparity in Reptiles: Introduction to the Symposiuln" Thonlpson and Blackburn, IIerpetologicalMonographs, 2006 Biology Brooker, Widmaier, Graham, Stiling, 2008

Primary Literature: Functional Ecology, Vol. 10, No.6 (Dec 1996) pg. 688-697, C*P. Qualls & R. Shine Bioscience, VoL 50, No.3 (Mar 2000) pg. 227-238, R. Andrews & Tom Mathies Herpetologica, Vol. 55, No.4 (Dec 1999) pg. 538-549, R. Shine & M. Lee Evolution, VoL 52, No.5 (Oct 1998) pg. 1441-1450, M. Lee & R. Shine

I am sorry, but I totany spaced on getting the article titles. Everything else is there, though.

7

Newsletter of the Minnesota Herpetological Society

October 2009

Volume 29

Number 10

Everything You Ever Wanted to Know about Feeding your Corn Snake Christina Danathar (I am not a professional or a veterinarian. This information comes only from my own research and experiences. )

Part Three: Tempting Reluctant Feeders You are going through all the correct steps in your feeding regimen. You have made any necessary environmental changes, and seen your vet. If there is still no sign of improvement in your snake's feeding habits, you can try doing different things to the food to make it more appealing to your snake. You should stick to your regular feeding schedule, only offering one food item at a time, and waiting about a week between attempts. These are some of your feeding options, in roughly preferred order: 1 - Frozen-thawed is the preferred regular feeding method; some snakes are scared of moving food;freezing,kH;ls baGteria,;and helps br,eak down cell walls.

2 - Try giving your snake all night (8 to 24 hours) to think about eating, and leave it alone - don't keep checking on it. Using a smaller container or covering the container with a towel may help minimize distractions.

3 - Try offering a smaller item, as it may be less intimidating and easier to digest; for very small baby snakes, try just the head of a pinky.

4 - Warmed up above room temperature, using warm - not boiling - water, or a heat lamp, to about 90-110 degrees.

5 - Re-frozen and re-thawed - but only re-freeze if the mouse was thawed for less than 2 or 3 hours; the cell walls break down further and the scent becomes stronger.

6 - Washed - rinse the pinky thoroughly in warm water, to wash off any scent.

7 - Scenting with adult mice - after washing the pinky, rub it on an adult mouse, or in the adult mouse's bedding; or keep frozen pinkies in the same bag with frozen adult mice.

8 - Braincasing - take an exacto blade or sturdy pin, stab the mouse's cranium, and squeeze a little fluid out - it's gross, but it works; the extra scent stimulates appetite 9 - Dipped in chicken broth - my vet suggested this one, which works on the same principle as braincasing.

8

Continued on next page

Newsletter of the Minnesota Herpetological Society

October 2009

Volume 29

Number 10

10 - Scenting with anoles - after washing the pinky, rub it on an anole; you can try using just a bit of the anole's skin or blood as well. Lizards are some of the first natural prey items a corn snake would seek in the wild.

11 - Try an alternate kind of prey - frozen-thawed rats, hamsters, or gerbils may be more tempting than mice of the same size. You may also try scenting mice with one of these.

12 - Try using tongs, hemostats, or chopsticks, and gently wiggle the mouse - it's moving prey that can't bite back. Just be careful not to scare your snake; wiggle gently and not too close to the snake's head.

13 - Fresh-killed (most places that sell live feeder rodents will do this for you; it's a good step between eating live to eating thawed) 14 - Live (some snakes like it lively; this is how they'd probably eat in the wild) 15 - Combinations of any of the above In most cases, an older snake (a year or more in age) will be tempted by one or more of these methods, or will eventually get hungry enough to eat. Once meals are being eaten regularly, you can start weaning the snake off these tricks and back to plain frozen-thawed mice. However, some baby corn snakes will simply refuse to eat - ever. It's sad, but I try to think of these as having been destined to become food for something else in the wild.

Keep an eye on your snake's shape, and try not to worry until they begin to look a little skinny. A healthy corn snake should be shap~d like a loaf of bread - the belly should be. flat, and the rest of the body should form an'upside-down U. If your ~nake is rounder than that (m'C)I"<e O-shaped), or begins to have a visible "waist" at the vent with a "bulging" tail, they are overweight - cut your feeding frequency in half for a few months (or permanently, if your snake is fully grown). If you can see a slightly "sunken" space on either side of the backbone, or the outline of ribs, and you've tried all the feeding tricks above at least three times each, it may be time for more drastic measures. See your vet - again - before moving on.

The next step - and likely the last hope - is force feeding.

An Update fr m Joe Wasilewski!

I have been working with burmese pythons in the Everglades, as they are becoming more common by the day. Google burmese pythons and/or my name and something should come up. I have been working on several TV productions for Ntl Geographic TV and the History Ch---a show called Monsterquest.

The Iguana Specialist Group is meeting in the island of Dominique and we will be reinvestigating the status of iguanas for the IUCN Red List of Endangered/Threatened species.

I am off to the Congo in October, spending the better part of the month there, attempting to catalog the reptile/amphibian species.

Work on the American crocodile continues in Costa Rica and we recently began a program to study crocodiles in Jamaica. We have already over 100 captures.

That is just a small portion of what I have been up to---I think my web page is up and running, check it out.

Rega rd s--------jw-----------Joe Wasilewski http://www.jadorallc.com

9

Newsletter of the Minnesota Herpetological Society

October 2009

lassified

I!II

dYe

Captive Bred (born 7 .. 21.08}

Volume 29

Number 10

III

ISing

English Spot

Dutch

"Can't Beat The Dutch"

Males:$110":120Females:$130~140

Will Deliver Locally/Meetings Mike Petersen- 651-780",:.9086 pete2204@umn~edu.

Sarah M. Richard

Fox Exotics 763-772-6 138 www.foxexotics.com

Find Me: (612) 781-9544 Bus: (651) 636·3760 Fax: (651) 639-6418 RealSarah@aol.com

RoseviHe Office 2803 Lincoln Dr. Roseville, MN 55113

Fine Captive Bred Ball Pythons, Color Morphs, Dwarf Boa Constrictors and Morel

Reptiles, Amphibians, Invertebrates, Small Mammals, Fish Complete line of Cages, Food, Books & Supplies for ~

(""''AtLcAnit1icils'"

HPc'V

A""c,;",~c

'.

Advanced Injury Rehabilitation, LTD. C'()lIlpreltl.msil'e Cltimpractic alld We/bleSS Care

Heather Ingbretson, D.C. Doctor of Chiropractic 1752 Lex.ington Avenue Roseville MN 55113 drhcntheringi>rctson(jiJyaboo.com

Phone (651) 487-5950 Cdt (763) 226-1129 Fax (651) 4R7-6016

Hours:

"OUR PATIENTS COil-IE FIRST"

Jeremiah D. Easter

n,,.

Owner

Ji

846 SW 132lld St. Burien WA 98146

The LARGEST, BEST selection in the Twin Cities Since

Mon .• Fri. 10 • 8 Sat. 10·6 Sun. 12 • 5

1978

F

TRADING CAlms

Join our facebook fan base today!

206·870-8085

Jeremiaheaster@gmail.com

www.DiamondbackTradingCards.com

REPTILES 2363 University Ave. W. S1. Paul (112 Blk E. of Raymond)

(651) 647·4479

www.twincitiesreptiles.net

GET TIE FACTS ... NOT THE HYPE

Wanted: Garage to rent. Prefer detatched, and must be secure. Location is open, but western suburbs would be great. Also need help with moving at the end of OctoberCall Gordon at 612-860-0331.

10

Minnesota Herpetological Society Membership Application New

Name _________________________________________________________________

Renewal

Others on membership _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Membership #

Address _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Type

City, State, Zip _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Check #

Phone# ______________ List in directory?

Yes

~E~m=a=il

__________________________________________

No

Herp related interests __________________________________

Active Memberships: Sustaining ($60/year) Contributing ($40/year) Basic ($20/year) Corresponding Memberships: Commercial ($25/year, 2 business card ads/year) Required check info. Drivers Lic#

DOB

State

Please enclose the proper payment with your application.

MAKE CHECKS PAYABLE TO: MINNESOTA HERPETOLOGICAL SOCIETY. Membership is for 12 months from the date of approval, a receipt will be sent only upon request.

MAIL TO: Minnesota Herpetological Society, Bell Museum of Natural History, 10 Church St. SE Minneapolis, MN 55455. Please allow 6-8 weeks f()r processing.

Advertising Policies MHS Ad Policy: The MHS assumes NO RESPONSIBILITY regarding the health or legality of any animal, or the quality or legality of any product or service advertised in the MHS Newsletter. Any ad may be rejected at the discretion of the Newsletter Editor.

Due to space limitations, unpaid and complimentary advertisements are subject to occasional omission.

Classified Ads: All active members are allowed a classified ad, run free of charge as space permits. Ads may be run (3) consecutive months, after which time they may be resubmitted.

Display Ad Rates: Ad Size per Month ~ page $10.00 % page $20.00 Full page $40.00 Business card advertisements may be purchased at $5.00 per ad, per month.

Submissions: All advertisements should be submitted to the MHS Editor, Bell Museum of Natural History, 10 Church St. SE, Minneapolis, MN 55455. Deadline is the night of the General Meeting for inclusion in the next newsletter. Make checks payable to: Minnesota Herpetological Society

Rats!

MRS Rodent Orders Mice Pinkies: Fuzzies: Hoppers: Adults:

$7/dz $7/dz $8/dz $10/dz

Rats Weaned: $ 17/dz Sm. Adults: $181dz Med Adults:$24/dz Lg Adults: $30/dz Jumbo: $36/dz

For pick-up at monthly meetings only! Orders must be placed 10 days in advance of the meeting in order to guarantee availability-Orders may be placed at the meeting for the following months order, or by emailing your request to: rodentorders@yahoo.com

Minnesota Herpetological Society Bell Museum of Natural History 10 Church Street SE Minneapolis, MN 55455-0104

Non-Profit Organization U.S. Postage PAID Mpls.MN Permit No. 2275

Address Service Requested

i

I

Mem# 152 Exp: 11/1/2009 Sally Brewer-Lawrence 1990 Iglehart Ave. St. Paul, MN 55104

)! Ii j I! J Ii} 111" 1J1,l1l j .;f sf, iI, II

J' ,I,I' ,I} 11i'TI i1111 j I

I;

I!

,I

Next Meeting: UNIVERSITY OF MINNESOTA- ST. PAUL CAMPUS

~ to l-iWf36

III

*=~::

:;

LARPENTÂŁUR

to

Sne{/ing~ !7l ?A!!<""r _lIliY <...4

Friday October 2, 2009 Room 335 Borlaug Hall, U ofM St. Paul Campus

S

..... lJtallk'l

,lhertl<lm (p.aflC!Il<Jt$ r.O/.IJ ...~ ;1,\i1bl..t).,.n rronl~

Ol)li;ouq

f.!..1I)

MHS Voice Mail: 612.624.7065

A N BUFORD

II ,I(1drt>()M~ pru'<"'1--:)o-

MHS Web Page: www.mnherpsoc.org

ro ~~

Printed on Recyled Paper: