FISHERY BULLETIN: VOL. 86, NO 1 



Table 3. — Continued. 



a 1.8:1 night:day catch ratio were represented 

 by fairly equal day {55-5T/( ) and night sam- 

 ples. 



TAXONOMIC PROBLEMS 



The 576 samples used for interannual compari- 

 sons yielded a total of 41 taxa including 19 spe- 

 cies, 7 genera, and 11 higher taxa (Table 4). The 

 PL and most mesopelagic forms were identified to 

 species. During several cruises there were large 

 proportions of small Diogenichthys spp. (Myc- 

 tophidae) larvae which could not be identified to 

 species. As a consequence, data on the two spe- 

 cies, D. atlanticus and D. laternatiis, were lumped 

 to permit reasonable between-year taxonomic 

 composition comparisons. In all but one cruise, D. 

 laternatiis dominated (77-1007f ) the identifiable 

 Diogenichthys larvae. Total within-year Dio- 

 genichthys spp. abundances were multiplied by 

 proportions of identified D. laternatus and D. at- 

 lanticus larvae to provide between-year abun- 

 dance rankings for each species. 



Species identifications of coastal forms are lim- 

 ited by inadequate taxonomic information and by 

 the presence of generally early larval develop- 

 mental stages in samples. These larvae are pri- 

 marily classified at familial and ordinal levels. 

 Because the classifications include few multispe- 

 cies groupings and those were numerically rare 

 the taxonomic limitations offer no severe analyti- 

 cal problems. 



Largest taxonomic problems occurred in 

 cruises when large numbers of small unidentifi- 

 able larvae were caught (e.g., 1972 and 1983; 

 Table 3). Additionally, most cruises had "miss- 

 ing" larvae (e.g., "other larvae" enumerated when 

 the samples were first processed but not ac- 

 counted for during later species identification 



work). With the exception of 1983 the uniden- 

 tified and missing larvae made up <5% of the 

 total larval abundance for each sampling pe- 

 riod. 



RESULTS 



Overall Ichthyoplankton Composition 



The 576 July-September samples used for in- 

 terannual comparisons yielded a total of 23,487 

 identified larvae. These larvae were dominated 

 (85.17r) by PL species (Table 4). Overall domi- 

 nants were anchoveta (Engraulis ringens; 74.37c) 

 and sardine (Sardinops sagax; 9.3%). The other 

 PL species were relatively rare: Trachurus mur- 

 phyi contributed 1.2% and Scomber japonicus, 

 Merluccius gayi , and Ethmidium maculatum to- 

 gether formed 0.3% of the total. The larval abun- 

 dances of these species off of Chile are strongly 

 influenced by sampling time and location. Mer- 

 luccius gayi occurs primarily to the south of the 

 study area (24°-43°S) and Scomber japonicus and 

 Trachurus murphyi have later summer (Novem- 

 ber-February) spawning peaks. 



The OL were dominated by mesopelagic fishes 

 (18 taxa, 10.6% of total larvae). Myctophids were 

 most abundant (8.0%) primarily because of the 

 large numbers of Diogenichthys spp., Lampanyc- 

 tus parvicouda , and Triphoturus mexicanus, 

 which together made up 7.7% of the total. One 

 bathylagid (Bathylagus nigrigenys) and one 

 gonostomatid (Vinciguerria lucetia ) were also rel- 

 atively abundant (together 2.5%). Coastal fish 

 larvae (14 taxa) made up 4.2% of the total; a 

 scorpaeniform (Normanichthys crockeri; 3.4%) 

 and blenniid (Blenniid D; 0.4%) dominated this 

 group. 



Eighteen taxa were relatively frequent (e.g., in 



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