123 



Aquatic Aife 



gold band on each side of it, above and 

 below being metallic blue. The sword is 

 intense yellow-green. The general color- 

 ation of the female is similar but not so 

 vivid, and she lacks the sword-like ex- 

 tension of the tail. Her dorsal fin is 

 somewhat smaller. 



Individuals vary considerably in size, 

 due mainly to environment and foods. 

 \\ 'hen a litter is given plenty of room, 

 abundant and proper food and adequate 

 warmth, large and sturdy specimens will 

 result. On the other hand if crowded 

 and poorly fed they will be scrawny and 

 small. In nature it attains a large size 

 for a cyprniodout, a male (including the 

 sword) reaching 6 l / 2 inches, the female a 

 trifle less. The average size for a mature 

 aquarium grown fish is y/ 2 inches. This 

 does not mean that large ones cannot be 

 grown in home aquaria. The writer has 

 in his collection a male, grown in a 24- 

 inch tank, that measures 6^4 inches in all. 



The number of young in a litter varies 

 with the size of the female, large ones 

 having families of a hundred or more. If 

 well fed the fry will mature in four to 

 five months. The best food is daphne, and 

 this is practically essential to rearing large 

 specimens in the aquarium. When ma- 

 ture the fish may be given dried foods, 

 such as dahpne, shrimp and similar sub- 

 stances. 



The swordtail does not thrive at tem- 

 peratures under 65 or over <So degrees, 70 

 to 75 being the happy medium at which 

 it will afford no end of amusement and 

 pleasure to its possessor. 



Concluded from page 121 

 stones and logs. By the alternate applica- 

 tion of their two sucker-like discs, they 

 are able to travel from one solid body 

 to another. One species (Arhynchob- 

 delloe ) arc able to swim in an eel-like 

 fashion. Of the British fresh-water 



leeches, one division possesses a tube-like, 

 telescopic proboscis. This organ is absent 

 in the other division, but some of its 

 members possess instead a rasp-like tri- 

 cuspid jaw. To the former division be- 

 long the Fish-leech {Piscicola geometra) 

 and the Chequered-leech (Protoclepsis 

 tessellata) , to the latter, the Horse-leech 

 (Hoenwpsis sanguisuga >, which does not 

 attack horses, the medicinal leech (Hirudo 

 medicinalis) and Dutrochet's Leech 

 ( Trocheta subviridis) . 



Leech farming does not seem to have 

 been practiced in England, although dur- 

 ing the first half of the nineteenth cen- 

 tury, the medicinal leech was a favorite 

 agent for blood-letting. The French, 

 however, specialized in leech-culture, too 

 often at the expense of poor decrepit 

 horses. 



Today — our lecturer informed us — ■ 

 leeches are still used in the East-end of 

 London by the alien population in cases 

 of neuralgia, gumboils, etc. The non- 

 alien population sometimes use them for 

 curing "black-eyes." 



Leeches which attack fresh water fish 

 are very active. The Fish-leech attaches 

 itself to weeds and stones by the posterior 

 suckers and waves its body about until 

 prey comes within its reach. It can swim 

 well, and it attacks most species of fresh 

 water fish, and may remain on its host 

 for some days. It is fairly common in 

 trout fisheries. 



Hemiclepsis marginata is a fairly active 

 leech, but is unable to swim. It is para- 

 sitic upon fish. It is an agent in the trans- 

 mission of certain trypanosomes which 

 infest fish. ( )n hatching, the young at- 

 tach themselves to the mother and leave 

 her about three weeks later. This leech 

 can be distinguished from the Fish-leech 

 by the seven logitudinal rows of yellow 

 spots which run along the back. The 

 ventral surface is without snots. 



