Tovar Mario O, Obando Martha J, Gómez Edwin, Caldas María L, Hurtado Hernán
Facultad de Ciencias Básicas, Universidad Militar Nueva Granada, Colombia.
Rev Biol Trop. 2009 Dec;57(4):1107-18.
The visual system of Teleost fishes has a wide range of adaptations. The eye has suffered modifications, mainly towards better sensitivity and visual resolution according to specific environmental conditions. In that way, this organ is so important for survival. In spite of being the most commercialized Orinoquia species, and one of the most important ornamental fish worldwide, there are almost no studies on the communication systems of P. axelrodi (including vision). We studied the eye in ten individuals of P. axelrodi, with a mean total length of 2.7 cm (SD = 0.2, n = 20). We measured eye relative size (TRO) after sacrifice. Heads were processed for hematoxylin-eosin, and 8 microm thick sections were obtained. Images were digitalized for histological identification and morphometrics. The relation between TRO and body length was 9.8% (SD= 1.1, n= 20); lens was spherical with a relative size of 64.3% (SD = 4.9, n = 20). Rete mirabilis choroid was composed mainly by capillaries, while sclera was composed of cartilaginous tissue. Retina with eight layers and two membranes. An areae centrales was observed in the posterior retina. Iris covered by a simple cubic epithelium. Cornea of endotelial tissue with two membranes. Pupil almost circular, with a naso-caudal elongation. Measures of retina thickness were as follows: lateral retina 144.5 microm (SD = 5.4, n = 20), temporal retina 210.4 microm (SD = 14.8, n = 20). Lens measurements were: dorso-ventral 759.6 microm (SD = 31.7, n = 20), antero-posterior 763.4 microm (SD = 30.7, n = 20). Cornea thickness was 27.6 microm (SD = 4.3, n = 20); iris thickness was 18.9 microm (SD = 1.9, n = 20); rete mirabilis choroid 22.2 microm (SD = 3.2, n = 20) and sclera: 15.9 microm (SD = 1.2, n = 20). This species has a typical Teleost eye conformation. The retina was thicker in the posterior area, probably related to the presence of neuron groups. This modification allows for a better sharpness and visual resolution. The TRO, areae centrales in the retina, and thin cornea, suggests the need of a well developed visual system resulting from a predatory diet.
硬骨鱼类的视觉系统有多种适应性变化。眼睛发生了改变，主要是为了根据特定环境条件提高敏感度和视觉分辨率。因此，这个器官对生存至关重要。尽管阿氏霓虹脂鲤是奥里诺科河流域商业化程度最高的物种之一，也是全球最重要的观赏鱼之一，但几乎没有关于该物种通讯系统（包括视觉）的研究。我们研究了10条阿氏霓虹脂鲤个体的眼睛，平均全长为2.7厘米（标准差 = 0.2，样本量 = 20）。在牺牲这些鱼后测量了眼睛的相对大小（TRO）。将鱼头进行苏木精 - 伊红染色处理，获得8微米厚的切片。对图像进行数字化处理以进行组织学鉴定和形态测量。TRO与体长的关系为9.8%（标准差 = 1.1，样本量 = 20）；晶状体呈球形，相对大小为64.3%（标准差 = 4.9，样本量 = 20）。脉络膜 rete mirabilis 主要由毛细血管组成，而巩膜由软骨组织组成。视网膜有八层和两层膜。在视网膜后部观察到中央区。虹膜被单层立方上皮覆盖。角膜为内皮组织，有两层膜。瞳孔几乎呈圆形，有鼻 - 尾向的伸长。视网膜厚度测量结果如下：外侧视网膜144.5微米（标准差 = 5.4，样本量 = 20），颞侧视网膜210.4微米（标准差 = 14.8，样本量 = 20）。晶状体测量结果为：背 - 腹径759.6微米（标准差 = 31.7，样本量 = 20），前后径763.4微米（标准差 = 30.7，样本量 = 20）。角膜厚度为27.6微米（标准差 = 4.3，样本量 = 20）；虹膜厚度为18.9微米（标准差 = 1.9，样本量 = 20）；脉络膜 rete mirabilis 为22.2微米（标准差 = 3.2，样本量 = 20），巩膜为15.9微米（标准差 = 1.2，样本量 = 20）。该物种具有典型的硬骨鱼类眼睛结构。视网膜在后部区域更厚，可能与神经元群的存在有关。这种变化有助于提高清晰度和视觉分辨率。TRO、视网膜中央区以及薄角膜表明，由于其捕食性饮食，需要发达的视觉系统。
