Wednesday, April 28, 2010

Mole-Rat Siblings

Pictured in the family portrait above are representatives from the three recent naked mole-rat litters born to Pacific Science Center.

The largest mole rat at the bottom of the picture is from Elphaba’s litter born on August 26, 2009, the first successful pups this colony has had in over two years. The mother gave birth to seven pups of which two still survive. These two remaining pups have thrived and grown to about 33 grams in the past eight months. As most of our adult naked mole-rats weigh between 50-60 grams, this means these guys are over halfway full-grown! Not too shabby!

The second-largest naked mole-rat (top left) is from the September 20, 2009 litter, which was the first successful litter for Galinda. From her litter of seventeen pups, six pups have survived and they are just trailing the members of the August litter in weight and size. They are now ranging between 24 and 32 grams. Our biggest problem is trying to tell them apart!

The smallest guy is from Galinda’s March 16, 2010 litter of nineteen. There are thirteen pups from that litter that are still alive and thriving today! We have not yet weighed them because they’re so small and we don’t want to injure them. However, they appear to have just about doubled in size since birth. They seem to be growing at a pretty healthy pace, comparable to the members of the older litters.

How big can our naked mole-rat colony get? Stay tuned because it looks like Galinda is pregnant again!

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Monday, April 26, 2010


What is that naked mole rat doing? Pacific Science Center's mole rat colony provokes this question frequently, but never more so than when animals solicit cecotropes.

The cecum (pronounced see-kum) is a portion of the digestive system in some species of animals, located between the small and large intestine. When food passes into the large intestine, the indigestible fiber is passed through as normal feces. However, portions that still contain nutrients are pushed back into the cecum where they are broken down into starches, sugars and vitamins. This material is then passed as cecal pellets or cecotropes, which the animal reingests.

Yes, the animal eats them. To a human, this is a strange concept. But to a naked mole rat with a diet high in fiber and low in calories, every bit of nutrition must be captured. By recycling nutrients that cannot be absorbed the first time, the animal is able to survive on a diet that would not support many other species. You can often watch a mole-rat assume a curled up sitting position allowing their head to reach far enough to ingest their own pellets.

Cecotropes are more than just nutrient-rich pellets. They also contain beneficial live cultures which the mole-rats need to properly digest their food. Baby naked mole-rats do not yet have these microbes and need to get them in order to survive. So as they begin to eat solid food, they will solicit older animals and beg for cecotropes. Late in her pregnancy, when her mobility is limited, the queen will also demand pellets.

Mole-rats do not normally produce these pellets on demand, and donor animals may be seen jumping or shaking violently in the process of producing them. Often when pups are involved, it looks as though an older animal may harm a pup, when in fact it is helping.

The ability and need to produce cecotropes may be part of the reason naked mole-rats are eusocial. All mammals need nutrition from their mother in the form of milk. For mole-rat pups, cecal pellets are a second form of necessary nutritive care, and one that can be provided by any member of the colony. This ability gives the queen a shorter turn-around time to focus her nutrient store on producing the next litter, while workers continue to provide for the existing pups.

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Friday, April 23, 2010

Fresh Sheet - April 23, 2010

“Fresh Sheet” is our weekly shipment report of pupae on display in the emerging window. Visit Pacific Science Center’s Tropical Butterfly House and meet our newest residents.

Costa Rica

10 - Agraulis vanilla (Gulf Fritllary)
37 - Anartia fatima (Banded Peacock)
11 - Battus belus (Belus Swallowtail)
20 - Battus polydamas (Polydamus Swallowtail)
11 - Caligo atreus (Yellow-Edged Giant-Owl)
11 - Caligo eurilochus (Forest Giant Owl)
11 - Caligo memnon (Owl Butterfly)
16 - Catonephele mexicana(Mexican Catone)
22 - Catonephele numilia (Numilia)
11 - Chlosyne janais (Crimson Patch)
20 - Colobura dirce (Mosaic butterfly)
29 - Danaus plexippus (The Monarch)
25 - Dryadula phaetusa (Banded Orange Heliconian)
12 - Dryas iulia (Julia Longwing)
26 - Heliconius charitonius (Zebra Longwing)
26 - Heliconius doris (Doris Longwing)
11 - Heliconius eleuchia (Eleuchia Longwing)
10 - Heliconius erato (Small Postman)
40 - Heliconius hecale (Tiger Longwing)
03 - Heliconius hewitsoni
34 - Heliconius ismenius (Ismenius Longwing)
10 - Heliconius melpomene (Postman)
11 - Heliconius sapho (Sapho Longwing)
09 - Heliconius sara (Sara Longwing)
13 - Heraclides anchisiades (Ruby-spotted Swallowtail)
17 - Hypna clytemnestra (Silver-studded Leafwing)
09 - Mechanitis polymnia (Polymnia Tigerwing)
38 - Morpho peleides (Blue Morpho)
34 - Myselia cyaniris (Blue Wave Butterfly)
11 - Papilio cresphontes (Giant Swallowtail)
16 - Papilio polyxenes (Black Swallowtail)
05 - Parides iphidamas (Iphidamas or Transandean Cattleheart)
11 - Phoebis argente (Apricot Sulfur)
35 - Phoebis philea (Orange Barred Sulfur)
17 - Siproeta epaphus (Rusty-tipped Page)
16 - Siproeta stelenes (Malachite)

Total = 648

We received a big shipment of pupae this week from Costa Rica including three species we rarely see: Heliconius eleuchia, Heliconius hewitsoni, and Phoebis argente. Come visit the Tropical Butterfly House and see them for yourself!

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Tuesday, April 20, 2010

Lydia Shedding

A few weeks ago, our Animal Caretakers and a few lucky visitors were able to witness something really special (and really cute!). Lydia, our adorable leopard gecko, was shedding! Luckily for you, one of our caretakers, Brianna Todd, had a video camera on hand, and was able to capture some of this remarkable activity.

Did you know that every animal sheds their skin? Even humans??? Humans, like most mammals, shed their skin pretty much constantly. Tiny particles of skin are sloughed from our skin all day long, although you may only notice it when you have dry, itchy skin or a sunburn. But check out that dust you’re collecting on the top of your book shelf or even on your coffee table, and you’ll find plenty of evidence for human shedding. A good portion of the dust that exists in our homes is made up of dead skin cells! Kind of gross right?

Lizards and snakes also shed their skin, although they actually make less of a mess than we humans. Because their skin is made up of scales, these reptiles must shed their skin all at once. In snakes, the shed skin will often come off in one piece. Because lizards have legs, it’s a little bit harder for them to shed in one piece, so it usually comes off in large pieces.

Many lizard species, including leopard geckos, eat their old skin as they pull it off. This may sound kind of gross but it’s actually another great adaptation. Not only does it leave no mess behind, it’s an efficient way for the animal to consume those extra vitamins and calories that are in their old skin.

But that’s enough talk for now. The video really says it all. So check it out, and the next time you visit Lydia at Pacific Science Center, congratulate her on a job well done.

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Saturday, April 17, 2010

Fresh Sheet – April 17, 2010

“Fresh Sheet” is our weekly shipment report of pupae on display in the emerging window. Visit Pacific Science Center’s Tropical Butterfly House and meet our newest residents.

El Salvador

25 - Battus belus (Belus Swallowtail)
20 - Caligo memnon (Owl Butterfly)
30 - Catonephele numilia (Numilia)
08 - Colobura dirce (Mosaic butterfly)
20 - Consul fabius (Tiger Leafwing)
10 - Heliconius charitonius (Zebra Longwing)
10 - Heliconius erato(Small Postman)
30 - Heliconius hecale(Tiger Longwing)
12 - Heliconius hortense(Mountain Longwing)
15 - Lycorea cleobaea (Large Tiger)
80 - Morpho peleides (Blue Morpho)
40 - Morpho polyphemus (White Morpho)
10 - Myselia cyaniris (Blue Wave Butterfly)
20 - Myscelia ethusa (Royal Blue Butterfly)
20 - Papilio thoas (Thoas Swallowtail)
15 - Prepona omphale=archeoprepona omphale (Blue Belly-Button)
20 - Tithorea harmonia (Harmonia Tigerwing)

Total = 385


40 - Battus polydamas (Polydamus Swallowtail)
40 - Heraclides anchisiades (Ruby-spotted Swallowtail)
04 - Heliconius erato (Small Postman)
50 - Heliconius melpomene (Postman)
20 - Dryas iulia (Julia Longwing)
50 - Catonephele orites (Orange-banded shoemaker)
40 - Anartia amathea (Scarlet Peacock)
06 - Hypna clytemnestra (Silver-studded Leafwing)
10 - Caligo memnon (Owl Butterfly)
30 - Mechanitis polymnia (Polymnia Tigerwing)
10 - Phoebis sennae (Cloudless Sulphur)

Total = 300

Can you guess which butterfly is pictured above? Anyone? Anyone?

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Thursday, April 15, 2010

Water Bugs in Love

Not to be outdone by the millipedes, the water bugs (members of the genus, Abedus) appear to have been experiencing springtime’s call to mate as well.

While the water bugs were never observed in the act of mating, they have been laying eggs.

There are many challenges that face aquatic animals looking for spots to lay eggs. Unpredictably changing water levels can leave eggs high and dry, or place the hatchlings too far below the water line. Predators love to snack on defenseless eggs. Even a single torrential rain can wash eggs off a formerly safe substrate and even physically damage them.

Water bugs have evolved an ingenious solution for these problems. The female deposits the eggs on the male’s back. Although the eggs slow him down as he moves through the water, the male is well able to take care of himself even with the extra passengers. Simply by behaving in ways that promote his own survival, his offspring are kept at the right water level and safe from harm until they hatch. Typical of the hemiptera or true bugs, the water bug has a piercing, sucking mouthpart. This mouthpart, called a rostrum, can give a painful jab to predators, just right for defending the father water bug and his young.

In our case, it seems that there were some extra eggs. The male had no more room, so the female deposited the remaining eggs on the surface of pump that recirculates water for the exhibit. Had the eggs remained there, it would have been a short life for the babies. The pump is powerful enough to pull them right in. So Animal Care staff removed the eggs, on the inactivated pump, into a hatchery where they can more safely develop and hatch.

Good luck to these eggs. We hope the extra care pays off. Remember to check back on this blog or visit Pacific Science Center’s Insect Village to follow up on the status of the hatchling water bugs!

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Monday, April 12, 2010

Millipedes in Love

As recently noted, spring has sprung at Pacific Science Center and that fact has not gone unnoticed in Animal Care. Late in the afternoon last week, Animal Caretaker Dan Warner noticed romantic activity in the Giant African Millipede terrarium. Two of our millipedes, Milton and Mildred, were in the beginning stages of courtship.

So what was going on? When he is ready to reproduce, a male millipede will undergo some important physical changes, in which his spermatophores (tiny packets of sperm) move from his gonopores, located on his 3rd body segment, to his gonopods, on the 7th body segment. Millipede gonopods are also called “sex-legs.” When Dan spotted the pair, Milton was walking along Mildred’s back. The rhythmic movement of a male’s legs let the female know that he is attracted to her. Soon the female raises her front segments to allow the male to encircle her. When their sex organs are in the right positions, the spermatophore is transferred to the female. [I’m kicking myself for not taking a photo of this activity! –ed.]

If Mildred’s eggs were successfully fertilized, she will soon be building an underground nest for her eggs – as many as 2,000! We might even see the first neonates (babies) within three weeks! African Giant Millipede neonates are white with only three pair of legs on a few body segments. They’ll have to go through many molts, adding body segments with four legs before they reach maturity.

Conversation in the Life Sciences department got us wondering: What would be some good pick-up lines that a male millipede would use to attract a female? Or what might a female millipede say to attract a male? We decided to throw this discussion out to our readers.

Here’s a chance to show off your creativity. Just remember – this is a family blog! Don’t make us censor your comment.

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Friday, April 9, 2010

Fresh Sheet – April 9, 2010

“Fresh Sheet” is our weekly shipment report of pupae on display in the emerging window. Visit Pacific Science Center’s Tropical Butterfly House and meet our newest residents.


40 - Danaus chrysippus (Plain Tiger)
40 - Cethosia biblis (Red Lacewing)
40 - Hypolimnas bolina (Great Eggfly)
20 - Papilio polytes (Polite Swallowtail)
40 - Graphium agamemnon (Tailed Jay)
70 - Parthenos sylvia philppensis (The Clipper)
20 - Pachliopta kotzeboea (Pink Rose)
100 - Idea leuconoe (Paper Kite)
20 - Doleschalia bisaltide (Autumn Leaf)
40 - Papilio rumanzovia (Crimson Swallowtail)
100 - Papilio lowii (Sunset Swallowtail)
30 - Papilio palinurus (Banded Peacock)

Total = 560

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Wednesday, April 7, 2010

Butterfly Census

Ever wonder how many butterflies made their home in the Tropical Butterfly House last year? Or how many pupae the Life Sciences Department placed in the emerging window? Can you guess how many different butterfly species we received in 2009?

Every year Life Sciences Manager Sarah Moore is required to provide the USDA with a document summarizing our data on pupae shipments. This information is carefully gathered by the staff each week as pupae are carefully inspected before placing them in the Emerging Window.

The 2009 census highlights are listed below:

Shipments received – 72
Different species received – 132
Pupae received – 24,578
Healthy butterflies released – 20,537
Parasitized pupae – 32
Percentage good emergence – 84%

Sarah credits her staff for the outstanding emergence statistics. “Eighty-four percent of pupae emerged as healthy butterflies, which is impressive considering that some shipments were delayed or arrived with problems. Staff really maximized the chances for every pupa to succeed. Their meticulous record keeping allows me to turn in data that I can be very confident is correct and thorough.”

So - Guess which species of butterfly is the most abundant in the Tropical Butterfly House? Frequent guests will easily recognize our beloved mascot, the Blue Morpho (Morpho peleides). We received 2,095 in 2009!

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Sunday, April 4, 2010

Blooming News

Spring has definitely come to Pacific Science Center, with a little help from our horticulture team, Jeff Leonard and Maida Ingalls.

Jeff and Maida just finished replanting the large planter bowls in the courtyard around the ponds. Previously, the bowls were full to overflowing with ornamental grasses and perennial flowers. They looked nice, but they needed constant watering and the plants and flowers were gradually crowding themselves out, blooming less as their roots competed for limited space.

The new plants will put on quite a show. Jeff and Maida were aiming for year-round appeal, and made sure each planter had at least a few evergreen plants to anchor the display during the winter months. Then they started adding flowers. They made their choices with pollinators in mind. Honey bees, bumble bees and local butterflies will love the wide selection of colors and bloom types, and the long flowering season will keep them coming back from early spring until the hard freezes of autumn. Some of the flowers to look for are Sedum, Echinacea, Delphinium, Scabiosa, Lithodora, and Rudbeckia.

Our courtyard is also home to a hummingbird, who will no doubt enjoy the Delphinium, Salvia, and Stock.

So next time you come for a visit, take a moment to step away from the exhibits and enjoy the plantings. The courtyard is full of color, texture and scent. If you come in the next few days, you will enjoy the added bonus of viewing our crab apple trees in full bloom.

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Friday, April 2, 2010

Fresh Sheet – April 2, 2010

“Fresh Sheet” is our weekly shipment report of pupae on display in the emerging window. Visit Pacific Science Center’s Tropical Butterfly House and meet our newest residents.

El Salvador

08 - Anteos maerula (Ghost sulfur)
30 - Battus belus (Belus Swallowtail)
40 - Caligo memnon (Owl Butterfly)
15 - Catonephele numilia (Numilia)
12 - Doxocopa laure (Silver Emperor)
30 - Heliconius hecale (Tiger Longwing)
80 - Morpho peleides (Blue Morpho)
40 - Morpho polyphemus (White Morpho)
40 - Myscelia ethusa (Royal Blue Butterfly)
10 - Papilio thoas (Thoas Swallowtail)
10 -Parides photinus (Queen of Hearts)
30 - Prepona omphale (Blue Belly-Button)

Total = 345

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