Histochemistry and functional organization of the dorsal skin of Ancistrus dolichopterus (Siluriformes: Loricariidae)

Abstract

The structural organization and histo-cytochemical features of dorsal skin of Ancistrus dolichopterus (acari bodo) are the main focus of this work. The epidermis, dermis and subcutis are the principal layers of the skin. The epidermis mainly consists of epithelial and mucous cells. Interspersed between them are lymphocytes, pigment cells, eosinophilic granular cells (EGC), and the taste buds as sensory structures. The high number of EGCs is implicated in general and specific immunological defense from pathogenic bacteria and multicellular parasites. The epithelial cells and mucous cells contain glycoproteins with oxidizable vicinal diols, carboxyl groups and O-sulphate esters and their high secretory activity is correlated with the bottom dwelling habit of this species. A thick stratum laxum contains overlapping osteoderms bearing denticles, and the stratum compactum make the integument thicker to help the fish in negative buoyancy for maneuvering near the bottom and protection. The entire body surface is covered by conical, backwardly directed denticles. These are composed of a dentine cone, surrounding a pulp cavity with the top covered by mineralized cap, and are the true homologues of teeth. These structures provide effective protection from abrasion and enemies. These structural peculiarities and histochemical features indicate additional physiological role of the skin of A. dolichopterus.A organização estrutural e aspectos histo-citiquímicos da pele dorsal de Ancistrus dolichopterus (acari-bodó) são os principais alvos do presente estudo. A epiderme, a derme e a hipoderme são as principais camadas da pele. A epiderme consiste principalmente de células epiteliais e mucosas. Intercalados entre elas estão os linfócitos, as células pigmentares, as células granulares eosinofílicas (CGE), e as papilas gustativas como estruturas sensoriais. Um grande número de CGEs está relacionado em geral com a defesa imunológica específica de bactérias patogênicas e parasitas multicelulares. As células epiteliais e as células mucosas contem glicoproteínas com grupos diol oxidáveis, grupos carboxilas e ésteres O-sulfatados sendo que sua alta atividade secretória está correlacionada com o comportamento bentônico, de fundo, dessa espécie. Um espesso stratum laxum contém osteodermos sobrepostos, parecidos com dentículos, e o stratum compactum que torna o tegumento mais espesso, contribuindo com a flutuação negativa necessária ao movimento perto do fundo e proteção. Toda a superfície do corpo é coberta por dentículos cônicos retrodirecionados. Esses dentículos são compostos por um cone de dentina, envolvendo uma cavidade pulpar e com o ápice coberto por uma capa mineralizada, verdadeiros homólogos dos dentes. Essas estruturas oferecem efetiva proteção contra abrasão e oponentes. Essas peculiaridades estruturais e aspectos histoquímicos sugerem a existência de uma função fisiológica adicional para a pele de A. dolichopterus.

Morphological and Histochemical Characterization of the Dermal Plates of Pleco (Hypostomus plecostomus)

“…Odontoblasts are distributed along the dentine, into which odontoblastic processes extend to establish dentine tubules. The denticle pulp cavity contains connective tissue and associated cells (Garg et al, 2010).…”

“…The dentine layer stains positive for PAS. In addition, the denticles are attached to fibers that are recognized by H&E and PAS, whereas the fibers are AB-negative (Garg et al, 2010). The affinity of the denticles of the skate L. erinacea for Hall and Brunt quadruple stain and Mallory trichrome and Weigert stain have also been examined.…”

Células Granulares Eosinofílicas/Células Mast (CGE/MC) y su relación con los efectos de herbicidas: Caso del Glifosato y surfactantes acompañantes en peces

“…Se ha demostrado por tanto, que los precursores no granulados de células granulares residen en el tejido y siempre que hay la disponibilidad de los factores necesarios, se convierten en CGE/MC , en otras palabras, las células se forman (Matsuyama and Iida, 1999) en órganos hematopoyéticos y posteriormente migran al tejido blanco, donde maduran y adquieren sus diferentes funciones (Da'as et al, 2012, Sfacteria et al, 2015. En los peces se encuentran con más frecuencia en la piel (Blackstock and Pickering, 1980, Zaccone, 1982, Gómez et al, 2013, así como en el tejido conectivo y epitelial del tracto digestivo y branquias (Reite, 1998, Matsuyama and Iida, 1999, Jordanova et al, 2007, Leknes, 2007, Alvarez-Pellitero, 2008, Garg et al, 2010, Dezfuli et al, 2011, Gomez et al, 2013; en sistema urinario, reproductivo, bazo, riñones, y vejiga natatoria. (Hellberg et al, 2013) las identificaron mayormente en el intestino de pez lobo (Anarhichas lupus L.), y al compararlas con trucha arcoíris, se evidenció que solo se asociaban estrechamente a vasos linfáticos en los primeros; además, en trucha arcoíris los gránulos de las CGE/MC tenían una estructura globular intacta, mientras que en pez lobo observaban vacuolas vacías.…”

New method of isotopic analysis: baseline‐standardized isotope vector analysis shows trophic partitioning in loricariids

“…The family, also called suckermouth armored catfishes, comprises~1000 recognized species in 100 genera that have diverse morphologies, particularly of the jaws , Armbruster et al 2018, Fricke et al 2020. This species-rich family is easily recognized by ossified plates that cover the body, integumentary teeth known as odontodes that cover bony plates and fin rays, and ventrally located jaws with an oral disk (Adriaens et al 2009, Garg et al 2010p. 201, Geerinckx et al 2011.…”

“…The family, also called suckermouth armored catfishes, comprises ~1000 recognized species in 100 genera that have diverse morphologies, particularly of the jaws (Lujan and Armbruster 2012, Armbruster et al 2018, Fricke et al 2020). This species‐rich family is easily recognized by ossified plates that cover the body, integumentary teeth known as odontodes that cover bony plates and fin rays, and ventrally located jaws with an oral disk (Adriaens et al 2009, Garg et al 2010 p. 201, Geerinckx et al 2011, Lujan and Armbruster 2012). Within their range from southern Costa Rica, Panama, and tropical to subtropical South America, loricariids are found in all freshwater rivers, from rapid Andean rivers to quiet brackish estuaries (Covain and Fisch‐Muller 2007, Armbruster et al 2018).…”