Editing Sirenia (section)

===Diet===
[[File:Dugong-rutger geerling.jpg|thumb|Dugongs sift through the seafloor in search of seagrasses.]]
Sirenians are referred to as "sea cows" because their diet consists mainly of [[seagrass]]. Dugongs sift through the seafloor in search of seagrasses, using their sense of smell because their eyesight is poor.<ref>{{cite journal |title=Dugong dugon Dugong |journal=Mammals of Africa: Introductory Chapters and Afrotheria |doi=10.5040/9781472926913.0013|year=2013 |isbn=978-1-4729-2691-3 }}</ref> They ingest the whole plant, including the roots,{{sfn|Berta|2005|loc=pp. 438–444}} although they will feed on just the leaves if this is not possible.<ref name="IUCNpdf"/> Using its divided upper lip, the West Indian manatee is known to consume over 60 different freshwater and saltwater plants, such as [[shoalweed]], [[water lettuce]], [[muskgrass]], [[manatee grass]], and [[turtle grass]]. An adult manatee will commonly eat up to 10–15% of its body weight, or {{convert|50|kg}}, per day, which requires the manatee to graze for several hours per day.<ref name="Proximate Nutrient Analyses of Four">{{cite journal|first1=Jessica L.|last1=Siegal-Willott|first2=Kendal|last2=Harr|first3=Lee-Ann C.|last3=Hayek|author3-link= Lee-Ann C. Hayek |first4=Karen C.|last4=Scott|first5=Trevor|last5=Gerlach|first6=Paul|last6=Sirois|first7=Mike|last7=Reuter|first8=David W. |last8=Crewz|first9=Richard C.|last9=Hill|year=2010|title=Proximate Nutrient Analyses of Four Species of Submerged Aquatic Vegetation Consumed by Florida Manatee (''Trichechus manatus latirostris'') Compared to Romaine Lettuce (''Lactuca sativa var. longifolia'')|journal=Journal of Zoo and Wildlife Medicine|volume=41|number=4|pages=594–602|jstor=40962301|pmid=21370638|doi=10.1638/2009-0118.1|s2cid=4884633}}</ref> By contrast, 10% of the diet of the African manatee is fish and [[mollusk]]s.<ref name=senegalensis>{{cite iucn |author=Keith Diagne, L. |year=2015 |title=''Trichechus senegalensis'' |errata=2016 |volume=2015 |page=e.T22104A97168578 |doi=10.2305/IUCN.UK.2015-4.RLTS.T22104A81904980.en |access-date=11 August 2021}}</ref> Manatees have been known to eat small amounts of fish from nets.<ref name="powell">{{cite journal| last = Powell| first = James| title = Evidence for carnivory in manatee (''Trichechus manatus'')| journal =Journal of Mammalogy| volume = 59| issue = 2|page = 442|year = 1978| doi = 10.2307/1379938| jstor = 1379938}}</ref> 

As opposed to [[bulk feeding]], dugongs target high-nitrogen grasses to maximize nutrient intake, and, although predominantly [[herbivore|herbivorous]], dugongs will occasionally eat [[invertebrates]] such as [[jellyfish]], [[sea squirt]]s, and [[shellfish]]. Some populations of dugongs, such as the one in [[Moreton Bay]], Australia, are omnivorous, feeding on invertebrates such as [[polychaete]]s{{sfn|Berta|2005|loc=pp. 438–444}} or marine algae when their supply of seagrasses is low. In other dugong populations in western and eastern Australia, there is evidence that dugongs actively seek out large invertebrates.<ref name="IUCNpdf">{{cite book|last1=Marsh|first1=H.|last2=Eros|first2=C.|last3=Hugues|first3=J.|year=2002|url=https://portals.iucn.org/library/sites/library/files/documents/2002-001.pdf |title=Dugong: status reports and action plans for countries and territories|publisher=International Union for Conservation of Nature|page=7|isbn=978-92-807-2130-0}}</ref> 

Populations of Amazonian manatees become restricted to lakes during the July–August [[dry season]] when water levels begin to fall, and are thought to fast during this period. Their large fat reserves and low metabolic rates—only 36% of the usual placental mammal metabolic rate—allow them to survive for up to seven months with little or no food.<ref>{{cite journal|first=Robin C.|last=Best|year=1983|title=Apparent Dry-Season Fasting in Amazonian manatees (Mammalia: Sirenia)|journal=Biotropica|volume=15|number=1|pages=61–64|jstor=2388000|doi=10.2307/2388000|bibcode=1983Biotr..15...61B }}</ref>