"Pearl organ" redirects here. For the obscure organ of a deep-sea fish, see Pearleye.
Nuptial tubercles on back of stone-roller, Campostoma anomalum
Nuptial tubercles (also called nuptial efflorescences, breeding tubercles or pearl organs)[1] are dermal structures present in 15 families of fish belonging to 4 orders of Actinopterygii – Salmoniformes, Gonorhynchiformes, Cypriniformes and Perciformes[2] – used in the courtship and reproduction process. They consist of partially or fully keratinised cells that form a perceptible protrusion in certain regions, used to stimulate females during courtship.[3] Their development is stimulated by hormones secreted by the pituitary and adrenal glands, and is induced shortly before the breeding season and discarded after. In some species, at least, there is a correlation between the level of androgens present in the endocrine system and the volume and complexity of tubercle growth.[4][5]
^"nuptial tubercle". Academic Dictionaries and Encyclopedias: Dictionary of ichthyology.
^Froese, Rainer; Pauly, Daniel (eds.). "Glossary Search for nuptial tubercle". FishBase glossary.
^Wiley, M. L. & Collette, B. B. (1970). "Breeding tubercles and contact organs in fishes: their occurrence, structure, and significance". Bulletin of the American Museum of Natural History. 143: 145–216.
^Raine Kortet; Jouni Taskinen; Anssi Vainikka & Hannu Ylönen (August 2004). "Breeding Tubercles, Papillomatosis and Dominance Behaviour of Male Roach (Rutilus rutilus) During the Spawning Period". Ethology. 110 (8): 591–601. Bibcode:2004Ethol.110..591K. doi:10.1111/j.1439-0310.2004.01002.x.
^Poncin, P., Matondo, B.N., Termol, C. et al. Relationships between circulating androgens, aggressive behaviour and breeding tubercles in males of the common bream Abramis brama L. in an aquarium environment. Fish Physiol Biochem 37, 533–542 (2011). https://doi.org/10.1007/s10695-010-9455-y
Nuptialtubercles (also called nuptial efflorescences, breeding tubercles or pearl organs) are dermal structures present in 15 families of fish belonging...
compound form of 2 or more levels, tubercles in amalgamated clusters or as tubercles forming, or joined by a ridge. Tubercles found on the leading edge of humpback...
the eggs. Males in breeding condition flush red and develop fine nuptialtubercles on their snouts, used for bumping and rubbing the females to induce...
water. Males undergo changes during the spawning season, developing nuptialtubercles on their backs and flanks, while their fins take on an orange hue...
Bangladesh. The species is sexually dimorphic with males developing nuptialtubercles. Vishwanath, W. (2010). "Bangana dero". IUCN Red List of Threatened...
at water temperatures of 19–21 °C (66–70 °F). The males develop nuptialtubercles on the head and paired fins. The fish spawn in slower-moving backwaters...
the breeding season, males grow small, keratin-based bumps, called nuptialtubercles, on their head, which are used in ritualized combat. This hardly ever...
snout–vent length. It is the fourth member of the genus to found nuptialtubercles on the thumb. The species can be found in thick vegetative areas with...
undergo sexual dimorphism by growing numerous sharp and colorful nuptialtubercles on their head, especially on their jaws, and fins. Their body shape...
over gravel riffles. During this breeding season, the male develops nuptialtubercles on various parts of the body including the head and fins. His coloration...
stripes and orange or pink coloration along the flanks, and develop nuptialtubercles on the tail fins. The black redhorse can be distinguished from similar...
base of the pectoral fins and sometimes near the mouth, and small nuptialtubercles on the top of the head, dorsal surface of pectoral rays, and on the...
believed to be related to size, with age being of secondary influence. Nuptialtubercles begin to appear on both sexes prior to the onset of the mating season...
vertical bars on anterior half. There are 14–17 pre-dorsal scales. Nuptialtubercles minute. Danionin notch present. Lateral line complete. There is a...
Prominent black lateral band from tail to snout Males develop minute nuptialtubercles on the head, nape and pectoral fin The bridle shiner is found in quiet...
fins, called nuptial spines or tubercles, and these are simple (solid-bodied, as opposed to bifid in some congeners). Nuptialtubercles are only seen...
there are small fleshy protrusions or spines sometimes referred to as nuptialtubercles. In other species of the genus, these are present in different ways;...
than females, with a ratio of 1.8:1 males:females. Occasionally, nuptialtubercles (small fleshy extensions on the anal or pelvic fins of male specimens)...
the type locality. The common name is an allusion to the diagnostic nuptialtubercles on the heads of breeding males. NatureServe (2013). "Macrhybopsis...
The juvenile fish are silvery. The adult males grow small white nuptialtubercles on the head and on a band extending from the head to the caudal peduncle...
Eigenmann (Characiformes: Characidae: Stevardiinae) with Comments on NuptialTubercles and Gill Gland in Characiform Fishes. PLoS ONE 14(7): e0217915. doi:10...
breed when temperatures are around 55–77 °F (13–25 °C). Males develop nuptialtubercles. Highfins have a lengthy spawning period and in Ohio were found spawning...
northwest part of the state. During the breeding season, males develop nuptialtubercles, particularly on the snout, internasal region, orbit, and underside...
be distinguished by its red fins, yellow tail spots, and smaller nuptialtubercles. "Pteronotropis" means "winged keeled back", which refers to the breeding...
season, when males display a much brighter green color than females. Nuptialtubercles in this species are absent. The name harlequin darter refers to mask-like...
respectively. It can be diagnosed from R. pigus by the absence of nuptialtubercles, and having 39-43 scales on the lateral line (vs. 46–51) and 8-9 branched...
caballeroi demonstrates a sexually-dimorphic trait referred to as nuptialtubercles, wherein small, fleshy protrusions appear on the rays of the anal...
cheeks may be pinkish Breeding males develop fine, sandpaper-like nuptialtubercles on the head, pectoral fins and some predorsal scales. They also turn...
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