Lorisidae

(vertebrate zoology) A family of prosimian primates comprising the lorises of Asia and the galagos of Africa.

(Lorisidae)

Class: Mammalia

Order: Primates

Family: Lorisidae

Thumbnail description
Relatively small, fully arboreal mammals inhabiting tropical and subtropical forests; their most prominent features are marked reduction of the tail and of the second digits of the hands and feet, in association with their slow, deliberate locomotion involving powerful grasping

Size
Relatively small body size, ranging from the gray slender loris (head and body length: 8.5 in, 21.5 cm); tail length: virtually zero; body mass 9 oz (255 g) to the potto (head and body length: 15 in, 37.5 cm); tail length: 2.5 in (6.5 cm); body mass 2 lb 11 oz (1,230 g)

Number of genera, species
5 genera; 9 species

Habitat
Lorisids occur in a range of tropical and subtropical forest habitats

Conservation status
Vulnerable: 2 species; Lower Risk/Near Threatened: 2 species; Data Deficient: 1 species

Distribution
Forested areas of Africa, Asia, and Southeast Asia

Evolution and systematics

Together with the bushbabies (family Galagidae), the lorises constitute the monophyletic infraorder Lorisiformes, which is the sister group of the Lemuriformes (Malagasy lemurs). The Lorisiformes and the Lemuriformes together form a monophyletic assemblage of strepsirrhine primates, which are characterized by retention of the rhinarium (a moist area of naked skin surrounding the nostrils), by non-invasive epitheliochorial placentation and by the derived, diagnostic feature of a toothcomb containing 4 incisors and 2 canines in the lower jaw. The two subfamilies of lorisids (Lorisinae and the Perodictinae) are probably monophyletic subgroups. However, both subfamilies contain slender, small-bodied species and stocky, large-bodied species that are superficially similar but probably developed convergently.

The fossil record for lorisids is very limited. A few isolated teeth of Karanisia indicate that members of the family may have been present in Egypt during the late Eocene. A skull of the early Miocene genus Mioeuoticus from Kenya provides the earliest well-preserved evidence for the existence of the family. Fragmentary remains of the late Miocene Pronycticeboides shows that the family was present in the Indian sub-continent at least by that stage. Given this sparse fossil record, it is not possible to infer a reliable date for the origin of the lorisids.

It has been proposed, on technical grounds of priority, that the family name "Lorisidae" should be changed to "Loridae." Because the customary name "Lorisidae" has been used so widely and for such a long period of time, the International Committee on Zoological Nomenclature has recently validated Lorisidae.

Physical characteristics

Body shape varies from slender (angwantibos and slender lorises) to stocky (pottos and slow lorises), but in all species the tail is markedly reduced to virtually absent (more so in the Asiatic species than in the African species). The head is short and broad at the back; the snout is also short. The eyes are quite large and oriented obliquely upwards rather than directly forwards. The ears are medium-sized and covered with hair. The arms and legs are approximately equal in length. As in sloths, the circulatory system of the limbs is organized into a network of fine blood vessels (rete mirabile) to permit prolonged contraction of the muscles without exhaustion. In the hands and feet, the first digits (thumb and the big toe) are strongly divergent, permitting powerful grasping, while the second finger and toe are very short to vestigial, enhancing the pincer action. All digits (fingers and toes) bear nails, although the nail on the second toe is elongated and angled obliquely upwards to form a "grooming claw."

Distribution

Slender lorises occur in Asia (India and Sri Lanka), slow lorises are widely distributed in South-East Asia, and pottos and angwantibos occur in tropical/subtropical regions of West and Central Africa.

Habitat

Lorisids occur in a range of forest habitats. They most commonly inhabit evergreen tropical rainforest, but also occur in dry, semi-deciduous forest, scrub forest, swamps, and montane forest up to middling altitudes.

Behavior

All lorisids show cryptic behavior, moving slowly and deliberately through the trees while foraging. This seems to be their primary strategy for avoidance of predation. In fact, members of this family all have low basal metabolic rates, so they are probably constrained to slow movement for energetic reasons. All species show scent marking. They have specialized marking glands in the genital region (scrotal and vulval glands) and some of them (e.g., slender loris) perform "urine washing" in which the palms of the hands and the soles of their feet are impregnated with urine before being applied to the substrate.

Feeding ecology and diet

Members of this family typically consume a mixed diet of fruit and arthropods (mainly insects), and they may also eat small vertebrates and birds' eggs. The proportions of fruit and arthropods vary between species, with small-bodied species tending to be more insectivorous and large-bodied species tending to be more frugivorous. There is a common tendency to feed on insect species that are generally regarded as unpalatable. Some species include plant exudates (gums) in their diets, and the pygmy slow loris (Nycticebus pygmaeus) may be a specialized gum-feeder.

Reproductive biology

Most species typically have one offspring, but the pygmy slow loris often has twins. Prior to independence, the infant is typically carried around clinging to the mother's fur, and "parking" of the infant on a small branch while the mother is foraging seems to be characteristic of all species. Gestation periods are notably long relative to body size, ranging from 134 to 193 days according to species. All lorisids have non-invasive epithelichorial placentation, and are probably polygamous.

Conservation status

Four species are thought to be relatively common. No species are listed as endangered, but two are Vulnerable (Loris tardigradus and Nycticebus pygmaeus) and two are Near Threatened (Arctocebus aureus and Arctocebus calabarensis). One species, Nycticebus bengalensis, is listed as Data Deficient.

Significance to humans

Lorisids seem to be of no real significance to local human populations, although the larger-bodied species may occasionally be eaten.

Species accounts

Resources

Alterman, Lon, Gerald A. Doyle, and M. Kay Izard, eds. Creatures of the Dark: The Nocturnal Prosimians. New York: Plenum Press, 1995.

Bearder, Simon K. "Lorises, Bushbabies, and Tarsiers: Diverse Societies in Solitary Foragers." In Primate Societies, edited by Barbara B. Smuts, Dorothy Cheney, Robert M. Seyfarth, Richard Wrangham, and Thomas Struhsaker. Chicago: Chicago University Press, 1987.

Charles-Dominique, Pierre. Ecology and Behaviour of Nocturnal Primates. London: Duckworth, 1977.

Groves, Colin P. Primate Taxonomy. Washington, DC: Smithsonian Institute, 2001.

Jenkins, Paula D. Catalogue of Primates in the British Museum (Natural History) and Elsewhere in the British Isles. Part IV: Suborder Strepsirrhini, including the Subfossil Madagascar Lemurs and Family Tarsiidae. London: British Museum (Natural History), 1987.

Manley, Gilbert H. "Functions of the External Genital Glands of Perodicticus and Arctocebus." In Prosimian Biology, edited by Robert D. Martin, Gerald A. Doyle, and Alan C. Walker. London: Duckworth, 1974.

Martin, Robert D. Primate Origins and Evolution: A Phylogenetic Reconstruction. Princeton, NJ: Princeton University Press, 1990.

Schulze, H., and B. Meier. "Behavior of Captive Loris tardigradus nordicus: A Qualitative Description, Including some Information about Morphological Bases of Behavior." In Creatures of the Dark: The Nocturnal Prosimians, edited by Lon Alterman, Gerald A. Doyle, and M. Kay Izard. New York: Plenum Press, 1995.

Schwartz, Jeffry H., and Jeremy C. Beutel. "Species Diversity in Lorisids: A Preliminary Analysis of Arctocebus, Perodicticus, and Nycticebus." In Creatures of the Dark: The Nocturnal Prosimians, edited by Lon Alterman, Gerald A. Doyle, and M. Kay Izard. New York: Plenum Press, 1995.

Sussman, Robert W. Primate Ecology and Social Structure. Volume 1: Lorises, Lemurs and Tarsiers. Needham Heights, MA: Pearson Custom Publishing, 1999.

Charles-Dominique, P., and R. D. Martin. "Evolution of lorises and lemurs." Nature 227 (1970): 257–260.

Izard, M. K., and D. Rasmussen. "Reproduction in the slender loris (Loris tardigradus malabaricus)." American Journal of Primatology 8 (1985): 153–165.

Izard, M. K., K. Weisenseel, and R. Ange. "Reproduction in the slow loris (Nycticebus coucang)." American Journal of Primatology 16 (1988): 331–339.

Jurke, M. H., N. M. Czekala, and H. Fitch-Snyder. "Non-invasive detection and monitoring of estrus, pregnancy and the postpartum period in pygmy loris (Nycticebus pygmaeus) using fecal estrogen metabolites." American Journal of Primatology 41 (1997): 103–115.

Jurke, M. H., et al. "Monitoring pregnancy in twinning pygmy loris (Nycticebus pygmaeus) using fecal estrogen metabolites." American Journal of Primatology 46 (1998): 173–183.

Kadam, K. M., and M. S. Swayamprabha. "Parturition in the slender loris, Loris tardigradus lydekkerianus." Primates 21 (1980): 567–571.

Loannou, J. M. "The oestrous cycle of the potto." Journal of Reproductive Fertility 11 (1966): 455–457.

Müller, Ewald F. "Energy metabolism, thermoregulation and water budget in the slow loris (Nycticebus coucang, Boddaert, 1785)." Comparative Biochemistry and Physiolology–A 64 (1979): 109–119.

Müller, E. F., U. Nieschalk, and B. Meier. "Thermoregulation in the slender loris (Loris tardigradus)." Folia Primatology 44 (1985): 216–226.

Nekaris, K. A. I. "The spacing system of the slender loris (Loris tardigradus lydekkerianus) and its implications for slender loris social organization." American Journal of Primatology 51, Suppl. 1 (2000): 77.

Oates, John F. "The niche of the potto, Perodicticus potto." International Journal of Primatology 5 (1984): 51–61.

Ramaswami, L. S., and T. C. A. Kumar. "Reproductive cycle of the slender loris." Naturwissenschaften 49 (1962): 115–116.

Rasmussen, D. T., and K. A. I. Nekaris. "Evolutionary history of lorisiform primates." Folia Primatology 69 Supplement (1998): 250–285.

Schwartz, J. H. "Pseudopotto martini: a new genus and species of extant lorisiform primate." Anthropological Papers of the American Museum of Natural History 78 (1996): 1–14.

Schwartz, J. H., J. Shoshani, I. Tattersall, E. L. Simons, and G. F. Gunnell. "LORISIDAE Gray, 1821 and GALAGIDAE Gray, 1825 (Mammalia, Primates): Proposed conservation as the correct original spellings." Bulletin of Zoologic Nomenclature 55 (1998): 165–168.

Smith, R. J., and W. L. Jungers. "Body mass in comparative primatology." Journal of Human Evolution 32 (1997): 523–559.

Walker, A. C. "The locomotion of the lorises, with special reference to the potto." East African Wildlife Journal 7 (1969): 1–5.

Weisenseel, K. A., M. K. Izard, L. T. Nash, R. L. Ange, and P. Poorman-Allen. "A comparison of reproduction in two species of Nycticebus." Folia Primatology 69 Suppl. (1998): 321–324.

Wiens, F., and A. Zitzmann. "Predation on a wild slow loris (Nycticebus coucang) by a reticulated python (Python reticulatus)." Folia Primatology 70 (1999): 362–364.

Zhang, Y.-P., Z.-P. Chen, and L.-M. Shi. "Phylogeny of the slow lorises (genus Nycticebus): An approach using mitochondrial DNA restriction enyme analysis." International Journal of Primatology 14 (1993): 167–175.

[Article by: Robert D. Martin, PhD]

A family of nonhuman primates that includes the loris.

The noun has one meaning:

Meaning #1: slow-moving omnivorous nocturnal primates of tropical Asia; usually tailless
  Synonym: family Lorisidae

Lorids[1] Fossil range: Early Miocene–Recent PreЄ Є O S D C P T J K Pg N
Slender loris (Loris spp.)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Strepsirrhini
Infraorder:	Lorisiformes
Family:	Lorisidae Gray, 1821
Genera
Arctocebus Perodicticus Pseudopotto Loris Nycticebus

Lorisidae (or sometimes Loridae) is a family of strepsirrhine primates. The lorids are all slim arboreal animals and include the lorises, pottos and angwantibos. Lorids live in tropical, central Africa as well as in south and southeast Asia.

Contents 1 Physical Characteristics 2 Behavior 3 Diet 4 Reproduction 5 Classification 6 References

Physical Characteristics

Lorids have a close, woolly fur which is usually grey or brown colored, darker on the top side. The eyes are large and face forward. The ears are small and often partially hidden in the fur. The thumbs are opposable and the index finger is short. The second toe of the hind legs has a fine claw for grooming, typical for strepsirrhines. Their tails are short or are missing completely. They grow to a length of 17 to 40 cm and a weight of between 0.3 and 2 kg, depending on the species. Their dental formula is similar to that of lemurs:

Dentition
2.1.3.3
2.1.3.3

Behavior

Lorids are diurnal and arboreal. Unlike the closely related galagos, lorids never jump. Some have slow deliberate movements, whilst others can move with some speed across branches. It was previously thought that all lorids moved slowly, but investigations using red light proved this to be wrong. Nonetheless, even the faster species freeze or move slowly if they hear or see any potential predator. This habit of remaining motionless whilst in danger is successful only because of the leafy environment of their jungle home, which helps to conceal their true position.^[2] With their strong hands they clasp at the branches and cannot be removed without significant force. Most lorids are solitary or live in small family groups.

Diet

The main diet of most lorids consists of insects, but they also consume bird eggs and small vertebrates as well as fruits and sap.

Reproduction

Lorids have a gestation period of four to six months and give birth to two young. These often clasp themselves to the belly of the mother or wait in nests, while the mother goes to search for food. After three to nine months - depending upon species - they are weaned and are fully mature within ten to eighteen months. The life expectancy of the lorises can be to up to 20 years.

Classification

There are five genera and nine species of lorid.^[1]

• Order Primates
  • Suborder Strepsirrhini: non-tarsier prosimians
    • Infraorder Lemuriformes
    • Infraorder Lorisiformes
      • Family Lorisidae
        • Subfamily Perodicticinae
          • Genus Arctocebus
            • Calabar Angwantibo, Arctocebus calabarensis
            • Golden Angwantibo, Arctocebus aureus
          • Genus Perodicticus
            • Potto, Perodicticus potto
          • Genus Pseudopotto
            • False Potto, Pseudopotto martini
        • Subfamily Lorinae
          • Genus Loris
            • Red Slender Loris, Loris tardigradus
            • Gray Slender Loris, Loris lydekkerianus
          • Genus Nycticebus
            • Sunda Loris, Nycticebus coucang
            • Bengal Slow Loris, Nycticebus bengalensis
            • Pygmy Slow Loris, Nycticebus pygmaeus
      • Family Galagidae: galagos
  • Suborder Haplorrhini: tarsiers, monkeys and apes

References

Wikispecies has information related to: Lorisidae

1. ^ ^{a b} Groves, C. (2005). Wilson, D. E., & Reeder, D. M.. ed. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 121-123. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3/browse.asp?id=12100101. 
2. ^ Charles-Dominique, Pierre (1984). Macdonald, D.. ed. The Encyclopedia of Mammals. New York: Facts on File. pp. 332–337. ISBN 0-87196-871-1. 

v • d • e Extant primate families by suborder Kingdom Animalia · Phylum Chordata · Class Mammalia · Infraclass Eutheria · Superorder Euarchontoglires Strepsirrhini Cheirogaleidae · Lemuridae · Lepilemuridae · Indriidae · Daubentoniidae · Lorisidae · Galagidae Haplorrhini Tarsiidae · Cebidae · Aotidae · Pitheciidae · Atelidae · Cercopithecidae · Hylobatidae · Hominidae

v • d • e Extant species of family Lorisidae Kingdom: Animalia · Phylum: Chordata · Class: Mammalia · Order: Primates · Suborder: Strepsirhini Perodicticinae Arctocebus (Angwantibos) Calabar Angwantibo (A. calabarensis) · Golden Angwantibo (A. aureus) Perodicticus Potto (P. potto) Pseudopotto False Potto (P. martini) Lorinae (Lorises) Loris (Slender lorises) Red Slender Loris (L. tardigradus) · Gray Slender Loris (L. lydekkerianus) Nycticebus (Slow lorises) Sunda Loris (N. coucang) · Bengal Slow Loris (N. bengalensis) · Pygmy Slow Loris (N. pygmaeus) Category

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