Partial purification of the crowding factor from Carassius auratus and Cyprinus carpio

Abstract

Crowding factors are those substances released by fish, which, under crowded conditions, inhibit both their growth and reproduction and depress their heart rate. We have partially purified the crowding factor from goldfish and carp by following a heart-rate-depression assay. The heart-rate-depression activity eluted with the diglyceride fraction from both silicic acid pnd Sephedex LH-20. A slightly different activity eluted with the free sterols. The peak activity associated with the diglycerides has a distinctive ultravjolet spectrum distinguishable from that of phthalic acid esters, which arc also active i n the assay sytem and are found in fish tissues and fish water.Crowding factors are species-specific hormoncs secreted by fish and other aquatic animals which have been observed to inhibit their own growth and reproduction when in a small body of water. Greene ('70) has shown that the spawning inhibitor for goldfish could be extracted from the water by chloroform, although he did not purify it further. This inhibitor proved to be species-specific. Similarly, Yu and Perlemutter ('70) extracted a species-specific growth inhibitor from a crowded zebrafish tank using trichloroethane. This inhibitor was observed to cause cardiovascular ailments and high mortality in developing fish embryos, and to shorten the life-span of adult fish in addition to inhibiting growth. It was also observed to depress the heart rate of embryonic fish.We have found that a species-specific growth inhibitor could be extracted from the water of crowded goldfish using either trichloroethane, chloroform, or carbon tettrachloride; that these extracts also contained a species-specific, heart-rate-depressant activity which could be identical or similar to the growth inhibitor; and that this heart-rate-depressor activity could affect juvenile gold6sh as well as embryonic fish (Francis et al., '73). We have set up an assay to measure the heart-rate depression of a juvenile goldfish in water (Francis et al., '73), and have used this heart-rate-depressor assay to follow the purification of this factor from both goldfish and carp.

Modulation of fish growth hormone levels by salinity, temperature, pollutants and aquaculture related stress: a review

“…Whilst it is too early to draw any firm conclusions as to the physiological importance of elevated GH during crowding stress it is possible that elevations in GH is a short term protective response against limited oxygen availability during crowding stress. In addition, the role and importance of ''crowding factors'' that are chemical agents (pheromones) known to adversely affect growth of fish (Francis et al 1974;Pfuderer et al 1974;Solomon 1977) should not be overlooked as it is plausible that such factors could also act to regulate fish GH, during crowding.…”

Effects of stocking density and body physical contact on growth of sea cucumber,Apostichopus japonicus

“…). Previous studies have shown that several factors led to individual growth variation in animals, including environmental factors (Seymour ; Jobling & Baardvik ), social interaction factors (Jobling & Baardvik ; Sloman, Gilmour, Taylor & Metcalfe ), genetic factors (Wang, Hayward & Noltie ; Qian, Cui, Xie, Lei, Xiong & Yang ) and chemical mediator factors (Yu & Perlmutter ; Pfuderer, Willims & Francis).…”

Fish acute toxicity syndromes and their use in the QSAR approach to hazard assessment.

“…However, this approach has not been successful for hazard assessment primarily because there is a lack of correspondence between the physiological-biochemical endpoints and whole-animal responses (3)(4)(5) the use of physiological diagnostic tests to detect xenobiotics has provided limited utility in aquatic toxicology, as reviewed by Klaverkamp (1) on the cardiodepressor activity of phthalic acid esters (6)(7)(8).…”