Biology - Callitrichinae Flashcards
What do Callitrichids include?
Marmosets and tamarins
What distinguishes marmosets and tamarins from other NHPs?
- Small size (100 to 850 gram)
- Dental formula 2 (2/2, 1/1, 3/3, 2/2)
- Claws or falcula instead of nails on digits
- Little to no sexual dimorphism
- High frequency of twinning (80%)
What is unique about the first digit on each foot?
Specialized nail, called the hallux, which is opposable, whereas the thumb is not.
Describe scent-marking glands.
Circumgenital glands are well-developed sebaceous glands overlying enlarged apocrine glands that cover the labia majora and pudendum in female and scrotum in male. Sternal glands predominantly apocrine glands located on the anterior chest and may be focal or diffuse.
What distinguishes marmosets and tamarins?
Marmosets are smaller, with prominent incisor teeth that are the same length as the canine teeth (enables gnawing holes in trees and eating gums and exudates). Tamarins have longer canine teeth.
The Callitrichinae subfamily contains what seven genera?
Callithrix, Saguinus, Miceo, Cebuella, Callibella, Leontopithecus
Where are marmosets found in the wild (country and environment)? Where are tamarins found?
Marmosets: Brazil, savanna/forest habitats. Secondary or disturbed forests or edge habitats
Tamarins: Lowland neotropical rain forest from Panama to Bolivia and NE Brazil. Primary or secondary forest
What is the most important factor limiting group size in the wild? Are groups territorial?
Availability of food supply. Yes, territorial
What is a typical group size? What age is usually transient?
4-7 individuals. Subadults usually transient.
Common marmoset groups are typically composed of what individuals?
One breeding pair of the highest ranking male and female, with all group members contributing to infant rearing.
What is the typical makeup of a tamarin group?
Multimale-multifemale social structure, with groups of unrelated and related adults and offspring. Mating is usually polyandry, with multiple males copulating with the reproductive dominant female.
Which Callithrix genera are CITES status I?
C. aurita (Buffy-tufted ear) and C. flaviceps (Buffy-headed)
Which Saguineus genera are CITES status I?
C. oedipus (Cotton-top), martinsi (Bare-faced), leucopus (Silvery-brown), geoffroyi (Geofforoy’s), bicolor (Pied bare-face)
When are Callitrichids active? What do they spend their day doing (activity and percentage)?
Diurnal. 20% traveling, 30-60% foraging
Describe marmoset and tamarin diet. What item makes up a considerable time spent feeding of the marmoset?
Omnivorous. Marmosets spend considerable time consuming tree exudates and gums by gnawing on bark or consuming exudates released by other trauma. Tamarins eat more fruits but also consume tree exudates.
How is Callitrichid reproduction unique? What is unique about the other females? What is this caused by?
Usually only one adult female in an extended breeding group reproduces. Subordinate females, usually offspring, may or may not have an estrous cycle based on species. Generally, nonbreeding Callithrix and Sanguinus do not ovulate in presence of dominant female. Due to scent marking by dominant female.
What is the average length of the ovarian cycle of the common marmoset?
28.6 days
A marked rise in what hormone within 1 day postovulation is a useful indicator of ovulation?
Progesterone
Is there lactational anestrus in marmosets? How soon can estrus behavior and ovulation occur post-partum?
No lactational anestrus. Estrus behavior within 3 days post-partum, ovulation 9-11 days.
What is the length of the ovarian cycle in tamarins? How do they differ from marmosets?
Shorter, 22.7 - 25.7 days. Tamarins do not have postpartum estrus.
What is the gestation length of the common marmoset? Saguinus?
Marmoset: 148 days
Saguinus oedipus: 168 days
Other Saguinus: 140-155 days
How early can pregnancy be detected? By what methods?
2 weeks. Measurement of plasma or urine placental chorionic gonadotropin or urine hydroxypregnanolone.
Describe ovulation in Callitrichids and how this impacts the number of offspring.
Polyovulatory. Dizygotic twinning is the rule
What occurs as a result of twinning? How is freemartinism avoided?
Blood chimerism due to placental vascular anastomoses. Females have an effective aromatizing enzyme system which converts androgens to estrone.
What are singletons typically the result of? What are they as a result?
Twin resorption. Commonly chimeric.
How does breeding in captivity and the wild differ?
No seasonality in the lab, seasonal breeders in the wild.
When are most young delivered? Lactation lasts for how long? When are young eating solid food and weaned?
Night. Lactate for 65-90 days, completely weaned by 100 days. Eat solid food at 30 days of age.
What are the negatives of hand rearing infants?
High failure rate, behavioral abnormalities, low cost-effectiveness.
Why does the reproductive capacity of callitrichids exceed that of other simian primates?
Postpartum estrus and twinning.
What is the sex ratio of callitrichid offspring?
1:1
When can first pregnancies occur? When do planned matings preferably take place?
As early as 1 year, typically take place at 1.5-2 years.
There is a high rate of infant rearing among what groups of females in some species? What is most infant loss associated with?
Primiparous captive-born females. Failure of young females to accept and nurse young.
