Morro Bay White Shark Dissection Protocol with Preliminary Results
by Henry F. Mollet, Dave A. Ebert, and
Corrine Davies

We acknowledge the Pelagic Shark Research Foundation for securing the specimen and arranging the dissection. We are most grateful to Dave Jessup DVM for the use of the dissecting facility at the Marine Wildlife Veterinary Care and Research Center of the California Department of Fish and Game in Santa Cruz CA.  We acknowledge suggestions by Barry Bruce, Dave Casper, Geremy Cliff, Leonard Compagno, Clinton Duffy, Malcolm Francis, Kirsten Gilardy, Rick Martin, Jeff Siegel, Wade Smith, and John Stevens. 



Scott Anderson (Scott D. will relay any info)
Dave Casper DVM (831) 459-3135,
Scott Davis, (831) 688-7281,
Dave Ebert, Ph.D. (831) 457-2794,
Brandy Faulkner, 650-493-0850,
Callaghan Fritz-Cope, 415-751-1474,
Dave Harris (Corrine D. will relay any info)

Jack Hawkes (Melissa M. will relay any info)
Randy Johnson, (415) 499-5742,
Melissa Miller
Henry Mollet Ph.D., (831) 375-5076,
Corrine Davis, DVM, Diplo. ACVP
Sean Van Sommeran, (831) 459-9346
Brent Wright 338-0449

Support and Observers

Jeff Reinhardt (831)883-0425; Billy Jakl (831)384-6903; May Ngyuen (408)294-4139 and other students as support and clean-up crew.
Some people from Bodega BBML and UC Davis will be attending as recipients and observers.
For information only: Carmel Babich, local enforcement director/


General information

Fred Arnoldy (skipper on the Rosa Lana Marie) caught a female white shark on 23 Nov 2000 (day after Thanksgiving) at around 9 AM when pulling up his halibut gill net about 3 miles out in Morro Bay Ca in about 30 fathom (60 m) deep water.  The shark wrecked FredŐs halibut gill net after getting entangled.  Fred figures it died while caught in the net, and others speculate it drowned while being pulled back to the harbor.  Among his helpers was Ken Wise, a longtime friend of FredŐs who runs a kelp harvester. Ken recalls seeing a great white 6-7 years ago but it was ŇonlyÓ 600 lbs. (272 kg). Shark weighed in at 1700 lbs. (771 kg) and measured 13 feet, 9 inches (4.2 m). (Weight was confirmed later with digital scale, TL measured during pre-dissection was a little higher (4.33 m).


Samples to be taken (Sean V. & Henry M.)

Note:  The head will get dissected at a later date to be scheduled. (Sean V.)
George Benz, Tennesse Aquarium, P.O. Box 11048, Chattanogga TN 37401, Any external parasites, gill arches, and olfactory sacs.  To be shared with PSRF.
Brandon Brown, Collect ampullary jelly.
Janine Caira, Dept. of Ecology and Evolutionary Biology, University of  Connecticut, Storrs CT. Tapeworms from stomach. .To
be shared with PSRF
Dave Casper
will be present to collect centra to be utilized for stable isotope studies.  .
Corrine Davis will be present to collect various tissue samples for histology (epigonal organ, nidamental gland, uterus, rectal gland and other assorted tissues (became 15!). 
Kevin Feldheim, 780 Weidner #203, Buffolo Grove, IL 60089. White muscle tissue sample
Kirsten Gilardi, Wildlife Health Center School of Veterinary Medicine University of California TB 128 Old Davis Rd. Davis, CA 95616. 1 gram (wet weight) each:  muscle, liver, brain for sturdy of environmental contamination of white sharks
Alexander Godknecht Center for Computing Winterthurerstr. 190 CH-8057 Zuerich, Switzerland. White muscle tissue sample.
Ken Goldman, VIMS, Fisheries Science Laboratory, P.O. Box 1346 Gloucester Pt., VA 23062. Eye and orbital retia. To be shared with PSRF.
Ed Heist,
Fish & Ill. Aquacul. Ctr. SIU, Carbondale, IL 62901-6511. White muscle tissue sample.
Cathy Jones
, Muscle tissue sample for DNA. Can be shipped in same envelope going to Amanda Pardini.
Andy Martin Dept of EPO Biology CB 334 University of Colorado, CO 80309. Andrew.Martin-1@Colorado.EDU.  Muscle tissue Sample for DNA.
Gavin Naylor, Biology Dept. ISU, Ames IA 50010. White muscle tissue sample.
Henry Mollet, will be present to collect complete reproductive tract, if necessary. Also will collect section of vertebrae from below first dorsal fin for aging study (MLML).  Save a few for Ken Goldman and Lisa Natanson/Wes Prattt. Remaining vertebrae PSRF.
Amanda Pardini Dept. of Zoology, Tillydrone Ave, University of Aberdeen, Aberdeen AB24 2TZ Great Britain. Heart tissue sample for DNA. Tooth to check if DNA can be extracted.
PSRF head, the fins, the vertebral column and various tissue, organ and dermal denticle patch samples.
Mahmood Shivji Oceanographic Center Nova Southeastern Univ. 8000 N. Ocean Drive, Dania FL 33004. Red and white muscle tissue samples for DNA plus fingernail size sample of any fin.
Doug Stoner address?. White muscle tissue sample.
Acknowledgments of receipt of samples from George B., Kevin F., Andy M. Amanda P., Mahmood S. Nothing from Alex, Gavin, and Doug (sent a sample a bit later)

Hi Henry,

    Sorry. I meant to write. The shark tissue you sent yielded very high

quality DNA. The sample is extremely valuable as we have so few sharks from California (only 13). I am really interested in sampling more white sharks from the eastern Pacific.



Tools needed (Sean V. and Henry M.)

Stainless temperature gauge with long shaft (4-8Ó).
2000 lbs. hanging scale, smaller scale to weigh smaller organs. 
Buckets with set of ropes for weighing organs. 
Tape measures of various lengths, calipers of various length,
Headboard or poles for large morphometrics (TL, FL, and PCL)
Appropriate dissection tools. Big sharp knifes. Scalpels for tissue samples.
Vials and plastic containers filled with 95% EtOH or 10% formaline for samples.
Extra plastic bags for saving larger organs plus coolers with ice for temporary storage.
30 garbage bags for disposal of leftovers.


Pre-dissection  (Dave C. , Sean V. & Henry M.)

16 Jan. 2001. ~NOON. Shark to be moved to the very large adjacent walk in refer for the first day or two to slowly begin the thaw.  Use stainless thermometer with long shaft to monitor temperature.  If it is not proceeding rapidly enough, pull it out into ambient air.  If it is thawing too rapidly, put it back in the big refer. CFG facility has small commercial ice making machines that produce both cube and crushed ice at about 50 lbs. per hour with a storage capacity of several hundred pounds.  If still icy inside, on day of dissection, use hose and spray body cavity to speed thawing.
Preliminary documentation and morphometrics depending on circumstances.
TL = 4.33 m , FL = 3.90 m, PCL = 3.49 m, girth 2.40 m, mass 772 kg.
There were some scars around the head, none appeared prominent in the usual places to suggest mating.

Brent Wright took photographs.  He is going to construct some very large pictures and print them life size.  He will try to construct a virtual reality shark, which does not look like it was frozen with a flat stomach. 

Dissection (Dave E., Dave C., Melissa C.)

Jan. 21, 2001. NOON.   
Document & photograph color patterns, axially spots, pigmentation, net marks, wounds, bites and scars.  Look for mating bites/scars, particularly around head, pectoral fins, dorsal fin, and trunk. Document location of ecto-parasites and save for PSRR and George Benz.

I know that I specifically mention to folks to record where they were

taken as I realize that their were probably more than a single species.

I wouldn't have guessed five, but certainly expected more than one.


As to their location. Most came from the pelvic fin region. Some were on

the ventral surface, others on the dorsal surface. Some were near the

cloacal area while others were definitely attached to the dorsal surface

of the pelvic fins. A few were taken from the dorsal fins. I believe

some were attached to the anterior margin of the D1. A couple were taken

from the base of the second dorsal.


I may have some photo's, but won't know until I get them back from the

photo processor next week.


> 4)    The while shark is known from my records to also have

copepods that specifically attach in the mouth, on the gills, and in the nose, were these  sites checked thoroughly?  If not, that's fine, but of course we need to  relate the examination details in our note as this host may have had even  more species on it!


I don't recall removing any from the head region as Sean wanted to

retain it for other purposes. The gills are probably fairly damaged by

now, but the nostrils and mouth may still have something. Although

having been frozen and thawed there's no telling what condition the may

be in.


> 5)    Was the shark moved about a lot (or frozen and thawed) before

being  sampled, such that copepods could have fallen off?  Some of the

copepods  certainly appeared damaged.  Please advise as to back ground

between captured and examination.


Henry could/has provided information on this aspect. Those on the pelvic

area were almost certainly damaged as the shark was moved about.


> 6) Is there anyway that the copepods could have represented

contamination of >sorts, say from those that had fallen off of other sharks?

I doubt it, but Henry could verify. All of the copepods were attached as

they probably were in life and appeared to have been frozen along with

the shark.


The sample you sent really is interesting.  It contains 5 species of parasitic copepods!  Globally, the white shark is infected with more than a half score of copepod species, however, I am unaware of any report of 5 copepod species all found on the general body surface of one host (host species aside).  I'm still gathering background information, but I think I might like to write up a short note on this interesting case.  Toward this end, I hope you can help me with the following questions:

Also: I noted 5 total species and 12 total individuals in the sample you

sent me.  Were there any other individuals collected, or was 12 it?

Full set of morphometrics measurements. Girth (2.0-2.5 m) requires a tape to be put down before shark is put on the ground. Weight to be taken with 2000 lbs. hanging scale when the shark is on a forklift. Was 1700-1800 lbs. (771-816 kg) dripping wet in Morro Bay.
Excerpt of morphometrics taken by Wade Smith, Joe Bizzarro, and Erica Burton in Morro Bay, Henry M. and Jeff Reinhardt during pre-dissection, Dave E. & Henry M. prior to dissection: TL = 4.33 m, FL = 3.90 m, PCL = 3.49 m, girth 2.40 m, mass 772 kg.  A full set of morphometrics using SELDATS IIII (LJVS 1986-9-4) data sheet was taken.

Remove fins.  Save PSRF. Small (fingernail size) fin sample for Mahmood Shivji.

Roll on left side (if possible) and do dissection on the right (side with functional ovary in mature females).
Was rolled on back and opened with one long lateral cut back to front.

Open right side with one, long lateral cut about halfway up the body cavity-then make one connecting cut perpendicular to the initial cut ahead of P1 and another perpendicular cut near P2. This makes a large flap that can be lifted dorsally (if possible) or cut-away in slices if the shark is too big.

Note. All internal organs were in excellent condition. For example, repro tract, after removal and quick storage in cold room, was looked at about 1 hr after it had been cut out. Dissection indicated that epigonal was still slightly frozen at beginning and had thawed completely toward end of partial dissection of left epigonal organ.

Remove liver (try not to pierce the gall bladder) and weigh it in chunks if necessary.  We expect each lobe of liver to weigh around 75-100 kg for a total of 150-200 kg (20-25%).  Save sample for PSRF. Not suitable (fresh enough) for RNA sample.  As per standard veterinary practice, multiple slice liver to check for looking for internal pathology.
Liver mass 122 kg (15.8%, 66.0 + 51.5 + 24.0 – 3 x 6.5).  Tail spine (barb) was found in anterior end of liver (near point where the two lobes adjoin) with pointed end sticking out 6-7 mm.  Barb is likely from bat ray.  Multiple slicing showed that the liver was clean (no pathology) and no other spines were found.

1. The spine appears to be that of a bat ray. I looked at some in the

collection including a bat ray spine taken out of a white shark and I

feel that that is what it is at this point. So let's go with that.

Remove stomach and valvular intestine (spiral valve) and weigh (expect 5 kg for spiral valve). Count spiral valves. Save PSRF.

Total mass 17.5 kg (2.27%) including 8.0 kg (1.04%) for spiral valve. Stomach basically empty with a smelly mass of 0.895 kg (0.116%) near the pyloric valve (weighed separately).  52 spiral valves.

Stomach content (look for remains of small animals such as squid beaks, fish otolith, fish bones etc and large ones. Save PSRF. Save tapeworms or other parasites from intestine. Put in 10% formaline for PSRF and Janine Caira.  Examine and weigh visceral retia (countercurrent heat exchanger, rete mirable).

Stomach empty apart from well digested smelly goo near pyloric valve (entry to valvular intestine). Sean strained it but found nothing. No tapeworms were found.
Rete 5.855 kg.

Remove and weigh (if possible) pancreas (expected weight 1 kg) and associated (with stomach) mesenteries.  Save PSRF.

Pancreas 1.645 kg.

Gastric lesion observation by Corinne Davies.  The stomach wall had a 14 x 8 cm region of thinning near the cardia. This region lacked rugal folds and the wall was approx. 1 cm thick, which was 1/3 to 1/2 the thickness of the surrounding gastric wall, which had well-developed rugal folds.  Along the margins of this thin region, there was a gradual loss of the mucosal folding pattern, i.e., no abrupt change in the mucosal lining.  The mucosa in the thinned region appeared similar in color and texture to the more folded regions of the remainder of the stomach.  The serosal surface in this area was unremarkable.  My impression is that this was not an inflammatory lesion -no reddening, no ulcer margin, no adhesions or scar tissue on the serosal surface indicative of a gut puncture. It seems that a spine might puncture the wall and seal over pretty rapidly; I'm not convinced it would leave such a large thinned area. Since I don't know where in the liver the spine was located, I cannot speculate about proximity to the stomach.  My husband photographed the ray spine as well as the affected area of stomach. I will be examining that area of the stomach as well as a more "normal" section.


Remove reproductive tract (expected weight 8 kg) comprising epigonal organs, oviducts with shell glands, if developed, isthmus and uteri.  Look for a hymen (membrane) in the opening of the vagina/uterus to determine if she has mated previously.  The epigonal organ is a soft pinkish-brown organ that runs along the back of the body cavity, wider at the anterior end (expect ~110+ mm) than posterior (expect ~10+ mm).  The ovary (expected to be size of small fist and weigh around 300 g) will be embedded near the front of the right epigonal organ and therefore will not be visible. Demarcation between epigonal organ and ovary may not be clear.  We donŐt expect to see individual ova within the ovary, but it is worth checking.  Check if there is any difference between left and right, given that so many sharks only have functional right ovary.  If we can locate ovary in the anterior part of the epigonal organ, dissect and take dimensions and weigh (in mature specimen there would be a central lumen and thousands of eggs/ovarian follicles and one would take small sample for later count). If we cannot find the right ovary, remove and freeze the entire epigonal organ and anything that looks like it might be reproductive organ for future investigation (Henry Mollet).  Measure uterine width at several points (front, mid, rear) and length. Shell gland dimension (& weight?) if developed. Check for uterine fluid?

The anterior end of the epigonal organ had numerous very small ovocytes (~1-2 mm diameter), but nothing larger.  The left (?see below must have been right) epigonal organ was slightly more developed than the right (left) . (After we cut out the reproductive tract it was stored in a bucket in the cold room and we could not tell left from right when it was examined in more detail later.  We have pictures prior to removing it that will verify which epigonal organ it was).

The nidamental (shell) glands did not look fully developed but the histological examine will confirm this. The uterus did not appear to be pendulous; it appeared to be fairly constricted and unlikely to have had embryos. The anterior end of each uterus was heavily vascularized (trophonemata?). My best guess is that it was maturing, but was still not quite there yet.

ItŐs possible that the ovary turned to mush, but I doubt it.  The internal organs were still semi-frozen when we opened her up and we were pretty careful in examining it prior to removing the reproductive tract. It will be interesting to see what the histology has to say.

Another observation is that while there were some scars around the head, none appeared prominent in the usual places to suggest mating.

Whole repro tract  (epigonal organs and uteri, plus rectal gland 7.620 kg (1.0%) saved in 10% formaline (H.F. Mollet).  DonŐt know how the rectal gland ended up with repro tract.  Sections of epigonal organ and uterine wall were also placed in formaline for histological evaluation (C.R. Davis). LotŐs of pictures were taken.

Changed from right to left below 11 Feb 2001

Left uterus, width 41.5, 56.4, 47.6 mm (anterior to posterior, check), length? (can measure later). UWI = 56.4*100/4333 = 1.30%.

moved from below epigonal organ. Showing possible trauma effect at transition from vascularized part to lower part about half way

Hi Corrine and Dave,

#112, of "congested" uterus was last photo taken. Last because we went back to have another look at it later after a student pointed it out to me. We were dealing with the left uterus, width 41.5, 56.4, 47.6 mm (anterior to posterior, check), length? (can measure later). UWI = 56.4*100/4333 = 1.30%.  Showing possible trauma effect at transition from "vascularized?" part to lower part about half way down. We did not observe any vascularized? section in the right uterus.


If you look at Fig. 16 in Mathews (1950) on basking shark, you see the uterus in mature basking sharks comprises 3 parts. At top is uterus lined with folds, then comes uterus lined with trophonemata, then vagina. I guess that it's possible that what looked like a possible trauma effect to you, could have been the beginning of the development of tophonemata. It has been suggested that mother-milk does play a role in perhaps the early stage of embryo development in lamnids (Gilmore for sandtiger). I don't know why this the developments of trophonemata had not started in right uterus. What do you suggest?>

Cheers, Henry

Note that Fig. 16 also nicely shows bifurcation of oviduct originating from functional ovary on right "inside" the epigonal organ. We had a hard time to tell the ovary from the epigonal organ in our immature female. The ovary sort of takes over the epigonal organ and the epigonal organ may start to shrink. In our immature white shark the epigonal was as long as the uterus, the schematic figure of the repro organs of a mature basking sharks shows a considerably shorter egigonal organ.
Right uterus,  width 47.5, 60, 42.6 mm (anterior to posterior, check) length? (can measure later). UWI = 60x100/4333= 1.38%
Left epigonal organ , width 117, 60, 17 mm (anterior to posterior), length 1210 mm. Showing possible trauma effect at transition from vascularized part to lower part about half way. Can be weighed later.
no longer sure if uterus or epigonal organ had this pronounced transition from more to less vascularized. Jpg#112 shows red, congested uterus, Last photo taken because we went back to have another look based on suggestion by one of GiacŐs students
Right epigonal organ , width 132, 59, 11 mm (anterior to posterior, much bulkier at anterior end compared to right, determine L or R by checking photographs when repro tract was cut out from body cavity), length 1215 mm. Can be weighed later, guesstimate is 0.5 – 1kg.

Corrine took section?
shell gland 35.1 wide x 64.4 mm long
Right shell gland (better visible, appeared to be slightly more developed) 39.2 mm wide x 64.6 mm long.  This gland was sectioned and placed in formaline for histological  evaluation (C.R. Davis).

Remove and weigh heart (expected weight 1 kg). Save PSRF. Heart tissue sample for Amanda Pardini

Heart 1.88 kg (0.244%)


Remove and weigh (if possible) spleen (expected weight 0.5 kg), kidney, and rectal gland. Save PSRF.
Spleen  0.40 kg (0.052%).

Fillet to expose the vertebrae. Vertebral count (expect 172-187, 99-108 precaudal, 68-83 caudal, count mono- and diplospondylous vertebrae; centrum diameter of largest vertebrae (expect 6-7 cm). Save PSRF. Cut out block of vertebrae (say 10) from below 1st dorsal fin and put on ice (for aging MLML, Henry Mollet).  Additional vertebrae to be saved for Ken Goldman and Lisa Natanson/Wes Pratt.  Centra also to be utilized for stable isotope studies.  Will try to detect the change in isotope signature inside the centra as the shark starts to predate upon mammals (Dave Casper).

Prelim. vertebrae count 94 + 21 + 70 = 185. Was X-rayed. Preliminary band count was 12.

White muscle tissue samples for Kevin Feldman, Alex Godknecht, Ed Heist, Cathy Jones, Andy Martin, Gavin Naylor, Amanda Pardini, Mahmood Shivji, Doug Stoner.  Red muscle tissue for  Mahmood Shivji.

Environmental contamination of white sharks. Tissue sample collection protocol by Kirsten Gilardi.

1) Please collect at least 1 gram (wet weight) each: muscle, liver, brain.  Ideally, muscle should be collected from dorsum, caudolateral from dorsal fin.  Use stainless steel instruments to handle tissue; it is preferable that the tissue samples not come into contact with aluminum foil, latex gloves or plastic surfaces.
2) Place each tissue in a separate glass jar (EPA clean jars, provided) and close lid finger-tight.  Label jar with:  date, location, shark identification number, age and sex of shark, tissue type, and initials of collector.  Place samples in jars in a <0C freezer (not at –80C  -- glass may break).
3) Samples stay at MWVCRC until someone goes to Davis.  Otherwise they would be shipped by Fed Ex overnight (next business morning).  An insulated container with blue ice is adequate for overnight shipping of the frozen samples.

Remove entire head and put aside for PSRF. Will get dissected later.  Eye and orbital retia for Ken Goldman. Weigh brain and examination for possible cerebral rete when dissecting head to remove jaw and chondrocranium.  Send brain to Glen Northcutt?  Eye and  orbital retia for Ken Goldman?  Parasites in olfactory bulbs for George Benz.  One or two teeth (replacement teeth from the back for Amanda Pardini? Measure tooth interspaces for Ralph Collier? Brandon Brown will collect ampullary jelly and document distribution of Ampullae of Lorenzini..

Hi Henry and Dave,


Thanks for the follow-up messages regarding the copepods collected from your white shark. That would be great if your photos provided more information regarding copepod attachment locations.


Regarding copepods associated with the he ad:

Check the jaws (between the teeth) and elsewhere within the mouth and on the gill arches themselves.

Also check on the gill filaments, on the capping tissue that covers the

efferent arterioles.

The 2 species of copepods that attach in the mouth and on the gill arches and on the gill filaments are each good size and can be easily seen with the naked eye.


Olfactory sacs: best to dissect them out and get some 10% formalin inside them and then send them to me to dissect further.  The copepods that reside in the nose are usually clear and relatively small.


Also: I noted 5 total species and 12 total individuals in the sample you

sent me.  Were there any other individuals collected, or was 12 it?

Again, thanks for including me.


Cheers and best fishes,



Hi Sean,


Recently I received a sample of copepods from the "Morro Bay white shark." The sample was interesting because although it consisted of only 12 individuals (and some were partial specimens) they represented 5 species. While all of the species are well known what's interesting about this is that the general body surface of 1 fish was infected by 5 species.  This would be worthy of a short note in an appropriate journal and hence I'm pursuing more information.


The copepods that I received came from about the vent.  Do you know if any other copepods from this fish were collected, and if so, is it possible for me to examine them?  If other copepods were collected I hope data on where they were attached was also collected.


In addition, the gill arches, gill filaments, interbranchial septa, jaws (between and about the teeth) and general buccal cavity of the white shark are known to be occasionally infected with up to 4 additional species of parasitic copepods.  Do you know if any where collected from these areas and if they are available?  If these regions have not yet been examined for copepods, will/can they be and can I learn of the results?


Lastly, the olfactory bulbs of this shark may contain yet another species of parasitic copepod.  To look for these small copepods one needs to carefully dissect out and fix (10% formalin) the olfactory sacs and then dissect them under a microscope.  It's good to gently squirt some fixative into the sac before plunking it into formalin so that the interior gets fixed rapidly.  I could do the dissections if the fixed sacs could be sent to me.


Please advise.  Once I've gathered all of the data regarding this case, I will write up a draft manuscript for all of the co-authors to sign off on. Seems as if you will be on this list.

Thanks for your help.



George W. Benz, Ph.D.

Director, SARI


Tennessee Aquarium and SE Aquatic Research Institute

One Broad St.

Chattanooga, TN 37401


phone 706 694-4666

fax 706 694-3957





Clean-up (Sean V.)

We expect around 1300 lbs. of remains. That would be 26 bags of 50 lbs. each.