Taxonomy, distribution, hybridization, morphological diversity and genetic diversity of red devil cichlids (Amphilophus spp.) in Taiwan

• Main Authors: Cheng Lin, 林承
• Other Authors: Hsiao-Wei Kao
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/51215298185067454488

碩士 === 國立中興大學 === 生命科學系所 === 105 === The common name of Amphilophus citrinellus and A. labiatus is red devil cichlids in Taiwan. Based on the morphology of lip, the species of A. labiatus has thick lip, and A. citrinellus has thin lip. Both of them were introduced into Taiwan as ornamental fish. Generally, these two species natively distributes in Nicaragua. However, these two species also can be found in reservoirs and ponds in Taiwan due to improper release. The aquarium industries created the blood parrot cichlid by artificial hybridization from two possible pairs (red devil cichlids and Paraneetroplus synspilus; red devil cichlids and Heros severus). Moreover, other hybrid cichlids (e.g. red mammon and flowerhorn) were created by the artificial hybridization of blood parrot cichlid, red devil cichlids and other Central American cichlids. However, the methods of artificial hybridization are commercial secrets in Taiwan without scientific studies. In previous studies, blood parrot cichlid was recorded in ponds in Taiwan. On the other hand, continuing improper release of blood parrot cichlid might cause genetic admixture of red devil cichlids with other cichlids. This study aims to investigate the distribution, taxonomy, hybridization, morphological diversity and genetic diversity of red devil cichlids in Taiwan. Ninety three red devil cichlids were collected from Sun Moon Lake (n = 44), Lotus Pond (n = 8), Jinshi Lake (n = 35) and aquarium (n = 6). Thirty one blood parrot cichlids were purchased from three aquariums. According to two color types of red devil cichlids (gold or dark morph), 86% of samples were gold morph, and 14% were dark morph. Specially, only one individual whose morphology was between red devil cichlids and blood parrot cichlid was sampled from Jinshi Lake, and named as devil parrot cichlid. Based on the ratios of lip to body area, the samples of red devil cichlids were divided into three groups (A. citrinellus, 62%; A. labiatus, 2%; the hybrid progeny of the two species, 36%). The morphometric analysis showed that the individuals of red devil cichlids were different in two ratios (body depth to body length and lip to body area). The geometric morphometric analyses revealed that the red devil cichlids in Sun Moon Lake had lower body depth and longer body length than that red devil cichlids in Lotus Pond and Jinshi Lake. Moreover, the morphology of the devil parrot cichlid was in-between the red devil cichlids and blood parrot cichlid. The sequences of mitochondrial control region (CR), cytochrome c oxidase subunit I (COI) and nuclear recombination activating gene 2 (RAG2) were amplified and sequenced. Based on the sequences of CR (n = 103) and COI (n = 103), red devil cichlids and blood parrot cichlid had 3 haplotypes, respectively. The haplotype diversities of the CR and COI sequence were 7.6 × 10-2 and 3.8× 10-2, respectively. The nucleotide diversities of the CR and COI sequence were 3.5 × 10-4 and 6.0 × 10-5, respectively. On the basis of the mitochondrial phylogenetic trees and minimum spanning networks, the haplotypes of red devil cichlids were same with the haplotypes of the populations in Lake Nicaragua and Lake Masaya. Based on the RAG2 sequences, Blood parrot and devil parrot cichlids were the hybrid progeny of red devil cichlids and P. synspilus; however, the samples of red devil cichlids did not have the alleles of P. synspilus. The populations of red devil cichlids were composed of A. citrinellus, A. labiatus, and hybrid progeny. The gold morph of red devil cichlids are common in Taiwan due to artificial selection. Besides, the red devil cichlids died when the water temperature was lower than 15 ℃. Therefore, the distribution of the red devil cichlids was limited in middle and southern Taiwan. The genetic diversities of the red devil cichlids were low because of the small amount of introduced individuals. In the further works, more samples and multiple nuclear genes are needed to examine the genetic admixture, and the relationship of morphological differences and ecological niches still needs more studies to be confirmed.