Toad fish

Since sea snake venoms are discussed here, it is appropriate to review other vertebrate venoms also. Unfortunately, very few investigations have been done on the venoms of other marine vertebrates. It is known that some fish secrete venoms from their spines. The fishes known to have venoms are the scorpion fish (family Scorpaenidae), weever fish (family Trachinidae), catfish (order Siluriformes there are 31 families), stargazers (family Uranoscopidae), toad fish (family Batrachoidi-dae), and stingrays (suborder Myliobatoidea). 

Haschemeyer, A.E. (1969). Oxygen consumption of temperature-acclimated toad-fish (Opsanus tau). Biological Bulletin, Marine Biological Laboratory, Woods Hole 136, 28-33. 

The next papers discuss another observation that various sexual abnormalities have been observed in wild populations of some toads, fish, and other reptiles. A link is then postulated that chemicals must be the cause of both. The argument is broadened when some pesticide classes are then thought to be partially responsible for breast cancer in women. 

The lateral diverticulum cells in semi-terrestrial species such as toads can still detect a wide range of amino acids, comparable to the properties of fish neuroepithelium. Both water-soluble and volatile odourants are discriminated by the olfactory neurones of the Clawed toad (Xenopus) (Iida and Kashiwayanagi, 1999). When single olfactory neurones were tested with acidic, neutral and basic amino acids, over 50% of the receptors gave some excitatory response. 

Fish discriminate between palatable and toxic prey. For instance, largemouth bass, Micropterus salmonides, reject the toxic tadpoles of the toad Bufo americanus but eat those of the spring peeper, Hyla crucifer [Kruse and Stone, 1984). 

DMT is found in the South American plants Virola calophylla and Mimosa hostilis, and in grasses, mushrooms, toads, grubs, and fish, and has been used by the Amazon natives for spiritual effects. DMT was synthesized in 1931. 

High dilutions of drugs have been used on human patients for a couple of centuries, and animal experimentation has been done only to confirm their therapeutic effects and study their mode of action. High dilutions have been found to produce effects on such animals as rats, mice, birds, toads and fishes. The basic principle is to create a disease in the animals and test appropriate remedies on them. Some models like catalepsy and righting reflex ones are non-sacrifice animal models which can be easily used to test the biological effects of potentized drugs. Potentized Nux vomica significantly reduced alcohol intake in rats and reversed to some extent... 

Proteolytic digestive enzyme activity in sluggish Black Sea fish (e.g. toad goby, scorpion fish) has been found to be equal to and sometimes greater than that of the active fish (e.g. horse-mackerel, annular bream, pickerel). The aminolytic activity of fish of low mobility is also greater (Ugolev and Kuzmina, 1993). It will further be shown in Chapter 5 that the consumption and assimilation of food occur more efficiently in sluggish than in active fish. 

Alkaloids are an important class of compounds that have pharmacological effects on various tissues and organs of humans and other animal species. More than 16,000 are known and most are derived from higher plants. Alkaloids have also been isolated from microorganisms, from marine organisms such as algae, dinoflagellates, and puffer fish, as well as from terrestrial animals, such as insects, salamanders, and toads. 

The lymphoid system of the amphibians is more complex than that of fishes. In addition to a well-defined thymus gland, primitive lymph node tissue is also present (Kent et al., 1964). In frogs and toads for the first time marked seasonal changes in thymic size are noted (Dustin, 1911). Reptiles have a lymphoid system that is quite similar to that seen in amphibians, including a well-developed thymus that also involutes with age (Dustin, 1911). 

Deoxy-5a-cyprinol 5a-Cholestane-3o,7a,12a,26-tetrol Some fishes some frogs and toads... 

Deoxy-5a-cyprinol, 5a-cholestane-3a,7a,12a,26-tetrol, has been identified as a minor companion of 5a-cyprinol in the carp bile [31]. This tetrahydroxy-5a-bile alcohol was prepared from anhydro-5a-cyprinol (VII) by lithium aluminum hydride reduction [2], 27-Deoxy-5a-cyprinol also occurs in bile of fishes [32], toads [9,33], and frogs [9]. 

There have been numerous descriptions of behavioral patterns elicited by chemical cues that logically should decrease predation risk (see Sect. 18.4). However, there have been just a few studies actually documenting the benefits of antipredation behaviors in crustaceans elicited by chemical cues and the best studies have been with other taxa. Work with several fish species (Mathis and Smith 1993 Mirza and Chivers 2001, 2003), the toad Bufo boreas (Hews 1988) and the wolf spider Pardosa milvina (Persons et al. 2001), has shown increased survival rates by prey that showed antipredation behavioral patterns following detection of chemical cues... 

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