Hernandez L Patricia, Staab Katie Lynn
*Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Suite 6000, Washington, DC 20052, USA; Department of Biology, McDaniel College, 2 College Hill, Westminster, MD 21157, USA
*Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Suite 6000, Washington, DC 20052, USA; Department of Biology, McDaniel College, 2 College Hill, Westminster, MD 21157, USA.
Integr Comp Biol. 2015 Jul;55(1):74-84. doi: 10.1093/icb/icv038. Epub 2015 May 14.
While much of the functional work on suction feeding has involved members of Acanthopterygii, an earlier cypriniform radiation led to over 3200 species filling nearly every freshwater trophic niche. Within the great majority of acanthomorph clades that have been investigated suction feeding and the underlying morphology responsible for the generation of rapid suction have been largely conserved. This conserved feeding-apparatus is often associated with increasing the force experienced by the prey item, thus making a strike on elusive prey more effective. Cypriniforms' trophic anatomy is comprised of a number of novelties used for benthic feeding, which characterized early members of this clade. The modified cypriniform structure of the oral jaws represents a situation in which a particular type of suction feeding allowed for probing the benthos with a more functionally maneuverable anatomy. Requisite evolutionary modifications included origin and elongation of a median kinethmoid, duplications of certain divisions of the muscles of the adductor mandibulae, and origin of a dorsal, intra-buccal muscular palatal organ used in winnowing detritus. The elongated kinethmoid (coupled with modified adductor muscles) allowed for a type of premaxillary protrusion that decoupled the upper and lower jaws, enabled premaxillary protrusions with a closed mouth, and facilitated benthic feeding by increasing functional flexibility. The resultant flow of fluid generated by cypriniforms is also quite flexible, with multiple instances of peak flow in a single feeding event. This greatly modified morphology allowed for a degree of kinematic maneuverability not seen within most acanthomorphs. Later cypriniform radiations into piscivorous, insectivorous, or planktivorous feeding guilds were associated with shortening of the kinethmoid and with simplified morphology of the adductor, likely involving an emphasis on ram feeding. Although this suite of morphological novelties seemingly originated within the context of benthic feeding, with minimal modifications these anatomical features were later coopted during radiations into different functional niches.
虽然关于吸食式摄食的许多功能研究都涉及棘鳍类，但早期的鲤形目辐射演化出了超过3200个物种，几乎占据了每一个淡水营养生态位。在绝大多数已被研究的棘鳍类分支中，吸食式摄食以及产生快速吸力的潜在形态在很大程度上是保守的。这种保守的摄食器官通常与增加猎物所受的力相关联，从而使对难以捉摸的猎物的攻击更有效。鲤形目的营养解剖结构由许多用于底栖摄食的新奇结构组成，这是该类群早期成员的特征。口颌的鲤形目结构改变代表了一种情况，即特定类型的吸食式摄食允许通过功能上更具可操作性的解剖结构来探测底栖生物。必要的进化改变包括中筛骨的起源和延长、下颌收肌某些部分的重复以及用于筛选碎屑的口腔内背侧肌肉腭器官的起源。延长的筛骨（与改变的收肌相结合）允许一种上颌前突的类型，使上下颌分离，能够在闭嘴时进行上颌前突，并通过增加功能灵活性促进底栖摄食。鲤形目产生的流体流动也非常灵活，在单次摄食事件中有多个峰值流量实例。这种极大改变的形态允许一定程度的运动机动性，这在大多数棘鳍类中是看不到的。后来鲤形目向食鱼、食虫或食浮游生物的摄食群体的辐射演化与筛骨的缩短以及收肌形态的简化有关，可能涉及对冲击式摄食的强调。尽管这一系列形态新奇结构似乎起源于底栖摄食的背景下，但这些解剖特征在向不同功能生态位的辐射演化过程中经过最小程度的改变后，后来被用于其他功能。
