FIG. 1.

(Color online) Neuromasts in teleost fishes. (A) Scanning electron micrograph (SEM) of a SN on the head of a larval cichlid (Aulonocara stuartgranti). Long kinocilium (kc, arrow) and multiple shorter stereocilia (= stereovilli; not visible) extend from the surface of the hair cells. Scale bar = 2 μm. (B) SEM of SN on the trunk of a newly settled juvenile goby (Elacatinus lori) with ciliary bundles (each has one long kinocilium, and several stereovilli, which are graded in length). Hair cells have opposing polarities (arrows) and are surrounded by non-sensory support cells (sc). Scale bar =1 μm. (C) Histological section through the mandibular canal (in lower jaw) in a cichlid (Labeotropheus fuelleborni). The canal is located deep in the dermis (d). Hair cells (hc) in the canal neuromast have prominent nuclei; non-sensory cells and mucus-secreting cells (blue). Meckel's cartilage (mc) and the LL canal are incorporated into the dentary bone (pink), Scale bar = 50 μm. (D) Histological section through a canal neuromast in the supraorbital canal of a juvenile cichlid (Tramitichromis sp.), located within the trough-like nasal bone (pink), which has not yet enclosed the neuromast within the canal. Two superficial neuromasts (sn) and the ciliated olfactory epithelium (oe) are visible, Scale bar = 50 μm. Reprinted with permission from Webb, Collin, Kuciel, Schulz-Mirbach, Zuwala, Denizot, and Kirschbaum, “Sensory organs,” in The Histology of Fishes, 1st ed. Copyright 2019 Taylor and Francis Group, LLC, a division of Informa plc.