Occurrence of Natural Interspecific Hybrids in the Pufferfish, Genus Takifugu, and Their Tetrodotoxin-accumulating
Ryohei Tatsuno1, Hiroshi Takahashi2
1Department of Food Science and Technology, National Fisheries University, Japan Fisheries Research and Education Agency, 2-7-1 Nagata-Honmachi, Shimonoseki, Yamaguchi 759-6595, Japan.
Abstract:
Pufferfish in the genus Takifugu accumulate the potent neurotoxin tetrodotoxin (TTX) in specific tissues that vary by species; nevertheless, certain species are consumed as a luxury food in Japan. Therefore, the edible species and tissues of Takifugu pufferfish are regulated in Japan. In recent years, unidentifiable individuals with atypical morphological characteristics caught in waters around Japan have been found to be natural interspecific hybrids among Takifugu species. Four cases of natural hybridization have been reported; in all cases, hybrids had external characteristics intermediate between those of the parental species. Although the frequency of these hybrids was generally low, it is high in certain parental species combinations. The TTX accumulation in tissues of natural and artificial hybrids was investigated and it was inferred that TTX accumulation in the skin is dominantly inherited. However, information on hybrids' toxicity in Takifugu pufferfish remains insufficient, and further research is required to prevent TTX poisoning associated with them.
More Related Videos
Related Concept Videos
02:29Hybrid Zones
02:07FISH - Fluorescent In-situ Hybridization
01:24Testing a Claim about Population Proportion
There are two methods of testing a claim about a population proportion: (1) Using the sample proportion from the data where a binomial distribution is approximated to the normal distribution and (2) Using the binomial probabilities calculated from the data.
The first method uses normal distribution as an approximation to the binomial distribution. The requirements are as follows: sample size is large...
02:27Trihybrid Crosses
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...