How to distinguish Wuchang fish

In many parts of Henan Province, people commonly refer to Wutoutou, Sanjiao, and Changchun as "Wuchang Fish." However, the true Wuchang fish is actually the head of the fish. To clarify the confusion between two similar species — the "head lice" (likely referring to the *Coreius aericeps*) and the "triangle worm" (*Parabagrus fuscus*), here's a detailed comparison. First, let’s look at their body types. The head of the *Coreius aericeps* is more prominent, with a rhombus-shaped head, while the *Parabagrus fuscus* has a near-rhombus or slightly elongated shape. Their mouth structures also differ: the *Coreius aericeps* has a wide, flat arc-shaped mouth, whereas the *Parabagrus fuscus* has a narrower, horseshoe-shaped mouth. Next, their tail structures are distinct. The tail of the *Coreius aericeps* is roughly square in shape, with similar height and length, while the *Parabagrus fuscus* has a longer tail than its height, giving it a rectangular appearance. The dorsal fin spines also vary — those of the *Coreius aericeps* are shorter, about the same length as the head, while the *Parabagrus fuscus* has longer, more pronounced spines that extend beyond the head. In terms of scale counts, the *Coreius aericeps* typically has 13–17 scales along the lateral line, while the *Parabagrus fuscus* has 17–22. Their internal anatomy also differs: the middle chamber of the *Coreius aericeps* is significantly larger than the anterior chamber, whereas the *Parabagrus fuscus* has a much smaller middle chamber compared to the front. The upper eyelids are another distinguishing feature. The *Coreius aericeps* has small, thin, triangular upper eyelids, while the *Parabagrus fuscus* has larger, thicker, rectangular ones. Geographically, the *Coreius aericeps* is native to the middle reaches of the Yangtze River, particularly known for its high quality from Liangzi Lake in Hubei. In contrast, the *Parabagrus fuscus* has a broader distribution, especially in the northeast and the middle and lower reaches of the Yangtze River. Lastly, their feeding habits differ: the *Coreius aericeps* is primarily herbivorous, while the *Parabagrus fuscus* is omnivorous, adapting to a wider range of food sources. This comparison helps distinguish these two fish species, which are often confused due to similar appearances but have significant differences in anatomy, habitat, and behavior.

Epichlorohydrin (ECH)

Epichlorohydrin, 3-Chloro-1, 2 - epoxypropene, chloropropylene oxide ,ECH .

Molecular Formula: CH2OCHCH2Cl, C3H5OCl

Properties: It is a volatile, unstable colorless liquid with irritating odor similar to chloroform and ether. Molecular weight is 92.85, density, 1.1806g/cm3, boiling point, 116.11°C, freezing point, -57.2°C, refractive index (nd20), 1.4382, flash point (open cup), 40.6°C, and ignition point, 415°C. It is slightly soluble in water, miscible with many organic solvents, and able to generate azeotrope with a variety of organic liquids.

Main Applications:
Epichlorohydrin is an important organic industrial chemical and a chlorine-consuming product in fine chemicals, mainly for producing epoxy resin, synthetic glycerin, epichlorohydrin rubber, nitroglycerine explosives, glass fiber reinforced plastics, and electrical insulation products, which are widely used in the chemical industry, light industry, transportation, medicine, electronics and other fields. It also can be used as solvent for cellulose ester, resin, and cellulose ether, and the raw material of plasticizer, stabilizer, surfactant, and chloroprene rubber.

Toxicity and Protection: It is highly toxic, absorbed through the skin, and irritating to skin and mucous membranes. In higher concentrations, it has the function of narcotism. When poisoning occurs, there will be eye irritation, conjunctivitis, rhinitis, lacrimation, cough, fatigue, gastrointestinal disorders, nausea and other symptoms. Serious poisoning may lead to anesthesia or even lung, liver or kidney damages. Lethal concentration of human beings is 20ppm. Lethal dose of rat is 5090mg/kg. The maximum allowable concentration in air is 5ppm (18mg/m3). Production equipment needs to be closed, air, circulating, and the operator, wear protective equipment. In addition, due to intense auto polymerization, epichlorohydrin can not be heated in the fire in case of container burst. As for reaction as reagent, it is appropriate to be diluted with inert solvent and slowly added.

Packaging, Storage and Transport:
As ferric chloride or stannic chloride can promote auto polymerization, epichlorohydrin should be stored in dry, clean iron barrel, 200kg each, and kept in a cool, ventilated, and dry place, away from fire and heat. Store and transport in accordance with the provisions of flammable toxic substances.

EPICHLOROHYDRIN SPECIFICATION DATA SHEET

ITEMS	GUARANTEED SPEC
PURITY% (m/m)≥	99.9
DENSITY g/cm3	1.180-1.183
COLOR(pt-co)≤	10
MOISTURE%(m/m)≤	0.05

Epichlorohydrin (Ech),Epichlorohydrin 106-89-8,99.9% Epichlorohydrin,High Quality Epichlorohydrin

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