User:Ssummers2015/sandbox

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Ssummers2015/sandbox
An Amazon river dolphin at Duisburg Zoo.
Size compared to an average human
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Superfamily: Inioidea
Family: Iniidae
Gray, 1846
Genera

see text

Iniidae is a family of river dolphins containing one living and four extinct genera.

Iniidae, also known as the Amazon River Dolphin or boto[1], can be found throughout the freshwater habitats of the Amazon rivers and Orinoco Basin[2]. The Amazon River Dolphin, genus Inia, is endemic to South America and the only extant genus of the family Iniidae.[3] Iniidae are highly morphologically different from marine dolphins, making them suited to their habitat[4]. Also, they display a high amount of sexual dimorphism, like color and size [1]. Seasonal movement between flooded plains and rivers is common due the variation of seasonal rain [5]. Very little is known about the South American River due to a lack of research [1]

Morphology[edit]

The river basins were flooded by marine waters, creating a new brackish habitat that allowed marine mammals to move into the Amazon River Basins. During the Miocene era, the sea level began to recede, trapping the mammals within the continent[4]. The Iniidea have adapted morphology common to freshwater, riverine habitats [3]. These adaption include cervical vertebra that are not fused, allowing for a flexible neck. Also, their dorsal (back) fin are highly reduced or absent so they do not become entangled in vegetation from the flooded terrestrial plains. Large and wide, paddle-like, pectoral fins allow for maneuverability in small vegetated areas [6]. Other riverine adaption including a long rostrum, skull and jaw, and reduced orbits[7]. Iniidae have many characteristic common of their marine odontocete relatives. Their stomachs include a fore-stomach, singled chambered main stomach, and a pyloric stomach with connecting channels. Also, iniidae have lost their fur and lack true vocal cord [8]. They share the similar structure of the tympanic bulla and lung shape, position of their diaphragm, and the position of the blow hole to the back of the head, with their marine ancestors.

Migration[edit]

Iniidae seasonally follow fish migration also. In the drier, seasons they are restricted to the deeper channels and found along flooded meadows and forest, and also near tributaries. Along the main river are floodplain lakes. The amount of river dolphins found here are seasonal, suggesting that the flood plains are favored. These flood plains are especially favored by females and the offspring that still rely on them for parental care. Since the water level fluctuates seasonally, no dolphin spends their entire life here. Also, the ratio of males to females in these lake systems is uneven. Females are more dominate in the floodplains, while males are congregated more in the rivers[1].

Feeding[edit]

Iniidae feed during the day and night but are most avtively feeding in the early morning and evening [6]. Fish were the only food for Inia to be recorded[9]. To find their food, biosonar is used. This short range biosonar allows them to locate their prey in shallow water enviroments, while helping them maneuver[10].

Sexual Dimorphism[edit]

Males are typical larger then the female river dolphins. Males are up to 16% longer and more than 50% heavier then their female partners, making them one of the most sexual dimorphic species of cetaceans. In general, male botos have a stronger hue of pink then females, while the most pink dolphins are nearly all males [1]. Juvenille Botos are gray, since their base pigment is gray. The scar tissue in this genus is pink. For many adults, their skin is covered in scars. Females tend to be less lacerated then the males. A cobblestone scaring pattern on caudal and dorsal fins are only found in males. This most likely gives rise to the intense pink color. The male iniidae genus is also known to use object in their sexual display, suggesting that the visual color may play a role in mate selection. Larger body size and pink color are consequences of sexual selective pressure [1].

Reproduction[edit]

Mating takes place from June to September, while the gestation period can last from 10 to 11 months. Species of Iniidae produce their offspring between May and July, to coincide with the dry season. With falling water levels fish are herded out of the flood plains, causing a high food availability[6].

Speciation[edit]

There is a debate on the number of species within the genus Inia. The main debate is whether there are two or three species and whether they can be considered sub-species. I. geoffrensis, I. humboldtiana and I. boliviensi, according to certain scientist are considered three separate species, while many consider I.geoffrensis and I. boliviensi to be the only two.[2] [11][5]. Martin in 2004 founded supporting evidence that genetic exchange between multiple sites of the amazon, even ones hundreds of kilometers away is possible.

Conservation[edit]

Inia dolphins are threatened mainly by human populations, in the country they can be found in. This includes incidental and even deliberate captures by fishers [2]. The deliberate capture of these dolphins is rare and illegal in Brazil. However, these types of activity have been reported in more northern areas of the country. Through interviewing of fishers, it appears that they are dislike, unwanted and in some cases hated by the fishers.[12]. Redlist has not yet classified this species, due to the lack of information on it.


I plan on adding information on diet and feeding behavior. Add categories such as feeding and morphology. The taxonomy is well covered so I will let that section be. Size and weight seem like they need to be included in the article. I will do my best to find sources for the statements in the existing article. If none can be found i will remove it from the article. My main goal will be to add general information from reliable sources.

Kristin's Peer Review[edit]

Hi Ssummers2015,

After reviewing the article you have chosen to edit, I have a few suggestions while you're editing:

  1. This article seems very new, so any information/citations you could add would be helpful
  2. Finding more information regarding habitat, range, diet, predators, a general description, physiology/adaptations, and their conservation status would help improve the existing article
  3. Maybe add some more pictures
  4. Also tag relevant information in the article, so readers can easily navigate through Wikipedia if they don't know what a term means.

Just some thoughts, happy editing!

-Ktreat88

  1. ^ a b c d e f Martin, A. R., & Silva, V. M. (2006). Sexual Dimorphism And Body Scarring In The Boto (Amazon River Dolphin) Inia Geoffrensis. Marine Mammal Science,22(1), 25-33. doi:10.1111/j.1748-7692.2006.00003.x
  2. ^ a b c Gravena, Waleska, et al. "Looking to the past and the future: were the Madeira River rapids a geographical barrier to the boto (Cetacea: Iniidae)?." Conservation Genetics 15.3 (2014): 619-629.
  3. ^ a b Gutstien, Carolina (2014). "The Antiquity of Riverine Adaptations in Iniidae (Cetacea, Odontoceti) Documented by a Humerus from the Late Miocene of the Ituzaingo Formation, Argentina". The Anatomical Record. 297 (6). Retrieved 4/1/18. {{cite journal}}: Check date values in: |accessdate= (help)
  4. ^ a b Hamilton, Healy, et al. "Evolution of river dolphins." Proceedings of the Royal Society of London B: Biological Sciences 268.1466 (2001): 549-556.
  5. ^ a b Rice, Dale W. "Marine mammals of the world, systematics and distribution." Society for Marine Mammalogy Special Publication 4 (1998): 1-231.
  6. ^ a b c Gomez-Salazar, C. (2011). Photo-Identification: A Reliable and Noninvasive Tool for Studying Pink River Dolphins (Inia geoffrensis). Aquatic Mammals,37(4), 472-485. doi:10.1578/am.37.4.2011.472
  7. ^ Pyenson, Nicholas D., et al. “Isthminia Panamensis, a New Fossil Inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the Evolution of 'River Dolphins' in the Americas.” PeerJ, PeerJ Inc., 1 Sept. 2015, peerj.com/articles/1227/.
  8. ^ Kaiya, Zhou. "Classification and phylogeny of the Superfamily Platanistoidea, with notes on evidence of the monophyly of the Cetacea." Sci. Rep. Whale Res. Inst 34 (1982): 93-108.
  9. ^ Layne, James N. "Observations on freshwater dolphins in the upper Amazon." Journal of Mammalogy 39.1 (1958): 1-22.
  10. ^ Ladegaard, Michael, et al. “Amazon River Dolphins (Inia Geoffrensis) Use a High-Frequency Short-Range Biosonar.” Journal of Experimental Biology, The Company of Biologists Ltd, 1 Oct. 2015, jeb.biologists.org/content/218/19/3091.
  11. ^ Ruiz-García, M., Banguera, E., & Cardenas, H. (2006). Morphological analysis of threeInia (Cetacea: Iniidae) populations from Colombia and Bolivia. Acta Theriologica,51(4), 411-426. doi:10.1007/bf03195188
  12. ^ Luiz Cláudio Pinto De Sá Alves, et al. “Conflicts between River Dolphins (Cetacea: Odontoceti) and Fisheries in the Central Amazon: a Path toward Tragedy?” Zoologia (Curitiba), vol. 29, no. 5, 2012, pp. 420–429., doi:10.1590/s1984-46702012000500005.
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