653 



SALMONID.E. 



SALPID.E. 



651 



Three pairs have been seen on the spawning-bed at the same time, and 

 even closely watched while making the furrow and laying the spawn. 



" The adult fish having spawned, being out of condition and unfit 

 for food, are considered as unclean fish. They are usually called 

 . kelts; the male fiah is also called a kipper, the female a baggit. With 

 the floods of the end of winter and the commencement of spring they 

 descend the river from pool to pool, and ultimately gain the sea, 

 where they quickly recover their condition, to ascend again in autumn 

 for the same purpose as before, but always remaining for a time in the 

 brackish water of the tideway before making either decided change, 

 obtaining, it has been said, a release from certain parasitic animals, 

 cither external or internal, by each seasonal change, those of the salt 

 water being destroyed by contact with the fresh, and vice versa." It 

 is moreover probable that the constitution of the fish is such as to 

 require a gradual change ; that the salmon is considerably affected 

 in piissins; from the salt water into the fresh, is evident from the 

 change of colour which accompanies the difference of the state of the 

 element. 



To Mr. John Shaw of Drumlanrig, Dumfriesshire, naturalists are 

 indebted for numerous important and interesting experiments insti- 

 tuted by him to determine certain doubtful points connected with 

 the natural history of the salmon, and more especially to determine 

 the developments and growth of the salmon-fry. Mr. Shaw's first 

 paper, entitled ' An Account of some Experiments and Observations 

 on the Parr, and on the Ova of the Salmon, proving the Parr to be 

 the Young of the Salmon,' will be found in the ' Edinburgh New 

 Philosophical Journal ' for July, 1836, vol. xxi. His second paper, in 

 which he gives an account of ' Experiments on the Development and 

 Growth of the Fry of the Salmon, from the Exclusion of the Ovum to 

 the Age of Six Months,' is published in the same work, vol. xxiv., p. 

 1C5; and lastly in the 'Transactions of the Royal Society of Edin- 

 burgh,' voL xiv., p. 547, the author gives a summary of the preceding 

 papers, and adds the result of further investigations. 



The author, who has lived the whole of his lif, with the exception 

 of a few seasons, on the banks of streams where salmon are in the 

 habit of depositing their spawn, had long been of opinion that the fish 

 commonly called the Parr, and supposed to be a distinct species from 

 the salmon, was the natural produce of the salmon ; and by a series of 

 very conclusive experiments he has evidently demonstrated the fact, 

 that Parr are young Salmon. 



The salmon has been known to attain upwards of 801bs. weight, 

 but a salmon of half that size is considered a line fish : " the largest 

 known, aa far as I am aware," observes Mr. Yarrell, " came into the 

 possession of Mr. Groves, the fishmonger of Bond-street, about the 

 season 1821. This salmon, a female, weighed 831bs. ; was a short fish 

 for the weight, but of very unusual thickness and depth. When cut 

 up, the flesh was fine in colour, and proved of excellent quality." 



Salmon have been kept in fresh-water lakes and other pieces of 

 water having no outlet to the sea ; these fish however, though of 

 tolerably good colour and flavour, did not obtain the size of those which 

 visited the sea annually. They are caught by nets of various kinds. 



The other British species of Salmo are : 



& trulta, the Salmon-Trout, Sea-Trout, or Phiuock. 



>'. fario, the Common Trout, Trout, or River-Trout. 



S. ferox, the Great Lake-Trout. 



& Levenentif, the Lochleven-Trout. 



X talvelinut, the Charr, Case-Charr, Alpine Salmon, Salvelian Charr. 



The plan of hatching the ova of the species of trout iu boxes before 

 permitting them to live free in their native haunts, has been found 

 very successful 



The following are the other principal genera of the Kalnionida : 



Ormerui. Of this genus the Common Smelt (0. eperlanus) affords a 

 familiar example. The smelts differ from the species of Halmo iu 

 having two ranges of teeth in each palatine bone, but there are only a 

 few in front of the vomer ; they have eight branchiostegous rays ; the 

 ventral fin is on a line with the anterior dorsal. They are taken in 

 the sea, and at the mouths of great rivers. Mr. Yarrell, in the 

 supplement to his volumes on ' Bristish Fishes/ describes a new 

 species of the present genus, which he names the Hebridal Smelt (0. 

 Hcbridicus), a name suggested by the locality in which the specimen 

 was found. 



Mallotiu, Cuvier. This genus is founded on a single species, the 

 Kalmo (jrmilandicus of Bloch, a small fish employed as a bait iu the 

 cod fisheries : its teeth are dense, like the pile on velvet, in both jaws, 

 as well as the palate and tongue ; the branchiostegous rays are eight 

 iu number ; the body is elongated and covered with small scales ; the 

 anterior dorsal and veutrala are situated rather behind the middle of the 

 body ; the pectorals are large and rounded, and almost meet beneath. 



Thymalltu, Cuvier. Of this genus the Grayling (T. vulgaris) is the 

 type. This fish is common in some of our streams, but is a local 

 apecie* ; it differs chiefly from the trouts or salmons in having the 

 mouth less deeply cleft, the orifice gquure, the anterior dorsal very 

 high, and the scales larger. 



C'omyonui, Cuvier. Here the teeth are very small, and the species 

 are often edentate ; the scales arc very large, and the first dorsal is not 

 so long as it is high in front. Numerous species of this genus are 

 found in Europe. The Qwyniad (0. fera, Cuvier) and the Yendace 



(0. Willughii, Jardiue) afford British examples of the genus. " The 

 Gwyniad of Wales," says Mr. Yarrell, " was formerly very numerous 

 iu Llyn Tegid (Pair Lake) at Bala, until the year 1803, when pike 

 were put into the lake, which have very much reduced their numbers." 

 It is very numerous in Ulswater and other large lakes in Cumberland. 



The Vendace was originally described by Sir William Jardiue, in 

 the third volume of the ' Edinburgh Journal of Natural and Geogra- 

 phical Science.' This author considered the fish in question as very 

 closely allied to the Salmo albula of Limueus, but the difficulty of 

 determining thU point has induced him to apply to it the name of 

 our distinguished naturalist. It is only known to inhabit the locks 

 iu the neighbourhood of Lochmaben iu Dumfriesshire. C. Lacepedie, 

 the Powau ; C. Pollan, the Pollan, are also British species. 



Argentina, Liuuoms. But one species (.4. sphynena, Linn.) of this 

 genus is known, an inhabitant of the Mediterranean. This fish has 

 the mouth horizoutally depressed ; the tongue is armed, as in the 

 trouts and smelts, with strong curved teeth ; in front of the vomer is 

 a transverse range of little teeth ; the brauchiostegous rays are six in 

 number ; the air-bladder is very thick, and loaded with that silvery 

 substance which is used iu colouring artificial pearls. 



Crumata, Cuvier. These are Salmonidw with the same general form 

 and small mouth, as observed in the Graylings, but differ iu the number 

 of the branchiostegous rays. 



Anaitomus of Cuvier differs chiefly from the last iu having the 

 lower jaw turned up in front of the upper one, and gibbous, so that 

 the little mouth appears like a vertical slit at the end of the muzzle. 

 The species inhabit the rivers of South America. 



The genus Gasteroplectus of Bloch also has the opening of the mouth 

 directed upwards, but the abdomen is compressed and prominent; 

 the ventrals are very small and far back; the first dorsal fin is situated 

 over the anal, which is long ; in the upper jaw are conical teeth, and 

 in the lower the teeth are sharp and denticulated. 



The species of the next genus, Serasalmo, are remarkable for the 

 short, high, and compressed form of the body, which is furnished with 

 small scales ; their teeth are eharp, of a triangular form, and denti- 

 culated; there is often an adpressed spine in front of the dorsal fin. 

 They inhabit the rivers of South America. To these may be added 

 the genera Tetragonopterus of Artedi, Clialceus, Myletes, Jlydrocyon, 

 Citharinus, Saurus, Scopdus, and Aulopus of Cuvier, and Xternopteryx 

 of Herman. 



SALPA. [SALPID.K] 



SALPID^E, or SALPA'CEA, a family of Animals belonging to the 

 the Tunicated division of the M oilmen, Lamarck places the genus 

 Xalpa in his third section of Tunicata(' Tuniciers Libresou Ascidiens'), 

 with the following definition : "Animals disunited, either isolated or 

 assembled in groups, without internal communication, and not form- 

 ing essentially a common mass." These form his second order of 

 Tunicata, with the title above given, and consist of the genera Salpa, 

 Ascidia, Bipapillaria, and Ma.mma.ria. Pyroioma is arranged under 

 his second section : " Animals floating with their common mass in the 

 bosom of the waters," in his first order (' Tuuiciers lldunis ou 

 Botryllairea '). 



These animals float in the open sea, and are characterised by a 

 transparent elastic external membrane which is elongated and open at 

 both extremities. The muscular fibres of the mantle, or membrane, 

 lining the cartilaginous tissue, are arranged in flattened bands. The 

 mouth and stomach, liver, and heart, are aggregated together into a 

 small mass near tha anterior aperture of the tunic; the intestine 

 extends towards the opposite aperture, and terminates freely iu the 

 common cavity of the mantle. A narrow plicated riband-shaped baud 

 extends across the internal cavity, which is the branchiae. The heart 

 communicates with a large vessel at each extremity, one of which is 

 ratuifred upon the visceral mass, the other upon the brauehisc and 

 muscular tissues. 



Whilst in the water the tunic expands and contracts. At each 

 expansion the sea-water enters by the posterior aperture, and is 

 expelled during contraction by the anterior one, its exit from tho 

 former orifice being prevented by a valve. It is the reaction of this 

 jet of water that causes the animal to move along. The currents which 

 thus pass through the animal yield nutrient matter, oxygenate the 

 chylaqueous fluid, and carry away from the animal the excretory 

 matters and the ova. 



The Salpce are divided into ' aggregate ' and ' solitary,' but these 

 are states of the same species. Each solitary Salpa has tho power of 

 producing from an ' internal stolon ' a number of other tialpa;, or now 

 individuals (Zooids). They are in fact buds, or germs, and afford an 

 instance of the gemmiparous method of reproduction. Each of these 

 zooids has an organisation resembling its parent, and some of them 

 possess an ovarium and ova, and others possess testes and spermatic 

 filaments, but the ova are not fertilised by the spermatic filaments of its 

 own set, but always by another. The result of the fertilisation of an 

 ovum is the production of a solitary Salpa, which now produces 

 again aggregated Salpce. This is one of the instances brought forward 

 by Steenstrup in illustration of his views of the alternation of genera- 

 tions. Here the first salp produces aggregated alps which are unlike 

 itself, but the aggregated salps produce solitary salps unlike their 

 parents, but resembling their grand-parents. It is the second genera- 

 tion to which Steeustrup has given the name ' Nurses.' 



