McDOWALL: SALMONIFORMS 



151 



not yet recognised origins within the diadromous stocks and 

 there is identifiable speciation related to known geo-tectonic 

 events. The relationships of some of the more distinctive species 

 groups— Neochanna (New Zealand), Galaxiella (Australia), and 

 including geographical outliers like Gala.xias zebratus (South 

 Africa) and Nesogalaxias neocaledonicus (New Caledonia)— re- 

 main obscure. Previous inclusion of Australian and South 

 American species in Brachygalaxias is ill-founded, on present 

 data, and confuses the understanding of relationships. 



An interesting phylogenetic problem in the Galaxiidae in- 

 volves the diminutive Tasmanian Paragalaxias. with four species 

 in high elevation lakes that probably pre-date Pleistocene gla- 

 ciations. Paragalaxias is distinctive in having the dorsal fin 

 origin only a little behind the pelvic bases. In this regard it 

 resembles aplochitonids differing from all other galaxiids in which 

 the dorsal origin is close to the level of the vent/anal origin. 

 Thus is Paragalaxias a galaxiid in which the dorsal fin has 

 migrated forwards, the resemblance to Aplochiton being con- 

 vergent or is it an aplochitonid in which the anterior dorsal fin 

 position is primitive but in which the adipose fin has been lost? 

 Examination of additional character complexes in which gal- 

 axiids and aplochitonids differ is needed to clarify this question. 



The preceding discussion makes it evident that relationships 

 between and within the southern diadromous salmoniforms re- 

 main in need of clarification. Only the Galaxiidae is large and 

 diverse enough to provide fertile ground for a study of within- 

 family phylogeny. In all the families, species and characters are 

 conservative in nature and lack distinctive or extreme speci- 

 alisation. Inter-specific differences tend to be expressed as changes 

 in meristic characters (like vertebral and fin ray counts), often 

 to presence/absence character states (pyloric caeca, canine teeth) 

 and sometimes to distinctive and stable differences in colour 

 patterning. There are few readily evident characters that are 

 indicative of major phyletic lineages. Possibly investigation of 

 laterosensory papillary rows will be informative. At present, 

 establishment of phylogenies appears difficult. A study of re- 

 lationships using DNA hybridisation techniques (Sibley and 

 Ahlquist, 1981) is at present in early planning stages. 



Life History Patterns and Reproduction 



In general life history patterns are understood although details 

 are sparse. There are broad similarities in patterns. 



Retropinnidae.— Aspects of early life history have been de- 

 scribed by Milward {1966 — Retropinna sewon/— Australia), 

 Jolly (1967-«. retropinna— N.Z.) and McMillan (1961— Sto- 

 kellia anisodon—N.Z.). The eggs are tiny— 0.5 to 0.6 mm in 

 lacustrine R. retropinna, 0.95 mm in R. semom. They are de- 

 mersal and adhesive, spherical, without distinctive features. They 

 are a pale straw colour. They are deposited on sandy bottoms 

 in lower river reaches or estuaries (around lake shores in land- 

 locked populations), where development occurs; development 

 is relatively slow ( 10-20 days) and description of development 

 shows nothing distinctive (Fig. 79). Newly hatched larvae in 

 some species go to sea. In others they are lacustrine or riverine. 

 Larvae at hatching are small (2-5 mm), very slender and elon- 

 gated, the yolk sac with a single oil globule, and situated ante- 

 riorly beneath the opercular openings/pectoral fins. The gut is 

 long, the vent at about 70% of length. A continuous finfold 

 encompasses the trunk. Pectoral fin buds are present. Newly 

 hatched larvae are positively phototropic. Pigmentation and 

 later development are undescribed. Juveniles from a summer- 



Table 36. Character States in Principal Genera of Southern 

 Freshwater Salmoniforms. (* except Paragalaxias; + present, - ab- 

 sent; u uniserial; m muUiserial; 1 parhypural + hypurals; 2 tubercles in 

 Lmetlia may not be comparable with others). Figures are "usual" al- 

 though variants are known. The divergent galaxiid genera are excluded 

 (Paragalaxias, Galaxiella, Neochanna, etc.). 



autumn spawning may return to fresh water the following spring 

 and are transparent and elongate; mostly mature adults return 

 one year later (age about 2 years) to spawn and die (see Jolly, 

 1967; McMillan, 1961; Milward, 1966). 



Protolroclidae.-lAXXXe is known of this family, with one species 

 extinct the other rare. McDowall (1976) and Berra (1982) have 

 described what is known of life histories. The eggs are small 

 (~ 1 mm) round and demersal, and are probably deposited in 

 upstream fresh waters. The larvae are not known but believed 

 to be carried to estuaries or the sea to develop, probably for 

 about six months, and return to freshwater in spring as slender 

 transparent juveniles (Fig. 80). 



Aplochilonidae. — \n Lovettia, mature adults migrate from the 

 sea in spring to spawn in fresh water, and are strongly dimorphic. 

 The male's reproductive opening migrates forward to the isth- 

 mus and the opercular flaps become elongated and papillated. 

 Fecundity is very low (=1 50-200). The tiny eggs (= I mm) are 

 demersal and spherical, and are attached in clusters to hard 

 surfaces (logs, stones, etc.) taking up to 23 days to hatch, and 

 the larvae drift downstream to sea. The post spawning adults 

 die. The life cycle is essentially annual. Larvae at hatching are 



