page_title: Commensalism
section_title: Types
hierarchical_section_title: Commensalism / Types
caption_attribution_description: English: A Pseudolynchia canariensis carrying phoretic mites. Français&#160;: Un diptère (Pseudolynchia canariensis) portant des acariens phorétiques.
context_page_description: Commensalism is a long-term biological interaction in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit from each other; amensalism, where one is harmed while the other is unaffected; and parasitism, where one is harmed and the other benefits. The commensal may obtain nutrients, shelter, support, or locomotion from the host species, which is substantially unaffected. The commensal relation is often between a larger host and a smaller commensal; the host organism is unmodified, whereas the commensal species may show great structural adaptation consistent with its habits, as in the remoras that ride attached to sharks and other fishes. Remoras feed on their hosts' fecal matter, while pilot fish feed on the leftovers of their hosts' meals. Numerous birds perch on bodies of large mammal herbivores or feed on the insects turned up by grazing mammals.
context_section_description: Like all ecological interactions, commensalisms vary in strength and duration from intimate, long-lived symbioses to brief, weak interactions through intermediaries.
caption: Phoretic mites on a fly (Pseudolynchia canariensis)
exif: {"Image Make": "NIKON CORPORATION", "Image Model": "NIKON D80", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Ver.1.01", "Image DateTime": "2008:06:03 11:25:26", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "336", "Image CustomRendered": "Normal", "Image ExposureMode": "Manual Exposure", "Image WhiteBalance": "Auto", "Image DigitalZoomRatio": "1", "Image FocalLengthIn35mmFilm": "150", "Image SceneCaptureType": "Standard", "Image GainControl": "None", "Image Contrast": "Normal", "Image Saturation": "Normal", "Image Sharpness": "Normal", "Image SubjectDistanceRange": "0", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "300", "Thumbnail YResolution": "300", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "28844", "Thumbnail JPEGInterchangeFormatLength": "9591", "Thumbnail YCbCrPositioning": "Co-sited", "EXIF ExposureTime": "1/80", "EXIF FNumber": "16", "EXIF ExposureProgram": "Manual", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2008:06:03 11:25:26", "EXIF DateTimeDigitized": "2008:06:03 11:25:26", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "4", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "4", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash fired, auto mode, return light detected", "EXIF FocalLength": "100", "EXIF SubSecTime": "20", "EXIF SubSecTimeOriginal": "20", "EXIF SubSecTimeDigitized": "20", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "2592", "EXIF ExifImageLength": "3872", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CVAPattern": "[0, 2, 0, 2, 1, 2, 0, 1]"}