Fisheries Research Bulletin No. 23 Fish Eggr and Larvae of the Hauraki Gulf, New Zealand by J. Crossland Fisheries Research Division I.[ew Zealand Ministry of Agriculrure and Fisheries Fish Eggr and Larvae of the Hauraki Gulf, I.{ew Zealand $r'- ¡- -j Fisheries Research Bulletin No. 23 Fish Eggr and Larvae of rhe Hauraki Gulf, New Zealand by J. Crosslan{ Fisheries Research Division, Ministry of Agriculture and Fisheries, Wellington, New Zealand Fisheries Research Division It{ew Zea\and Ministry of Agriculture and Fisheries 19Br Published by the New Zealand Ministry of Agriculture and Fisheries Wellington l98r ISSN 0l l0-1749 R¿c¿iu¿d 28 February 1978; reuisíon receiu¿d 4 June 1980 FOREWORI) Jnvrs CRossI-AND has already used the distribution and abundance of the eggs and larvae of snapper to assess the standing stocks of this most valuable species in New Zealand's most important cornmercial fishery. llowever, despite the rapid expansion of fishing effort over the past few years, our knowledge of the available resources, even in the Hauraki Gulf, has remained meagre. The data in this bulletin not only add to our undeistanding of the other species in the Hauraki Gulf, but are an important prerequisite to our appreciation oÍ its significance as a spawning or nursery ground {or fisheries elsewhere. At the same time, this type of information will be of value as a background for integrated management of the total resources of the area in the future. G. DUNcAN Weucn, Director, Fisheries Research Division CONTENTS Pog, INTRODUCTION il MATERIALAND METHODS 1l Sampling and Sorting 1l Identific¿tion of Eggs and Lawae ll Descriptions of Eggs and Laruae t2 Daø Presentation l2 RESULTS l3 Family Engraulidae 13 Family Clupeidae t4 Family Muraenidae t7 Family Congridae 20 Family Moridae. .. 20 Family Exocoetidae oq Family Trachichthyidae 22 Family Zeidae ... 23 Family Syngnathidae 23 Family Triglidae 23 Family Acanthoclinidae 2+ Famiiy Carangidae 26 Family Sparidae.. 31 Family Mugilidae 34 Family Labridae 34 Family Uranoscopidae 35 Families Blenniidae, Clinidae, and Tripterygiidae 5t) Family Eleotridae 38 Family Gempylidae 38 Family Scombridae 38 Family Bothidae +0 Family Pleuronectidae 4l Family Balistidae 49 Family Diodontidae 5+ DISCUSSION 56 Sampling Period 56 Effect of Temperature on Spawning.. 56 Effect of Water Movements on Distribution of Larvae . .. 57 SUMMARY 58 REFERENCES 59 ACKNOWLEDGMENTS ... 59 FIGIJRES Page l. The Hauraki Gulf, showing places mentioned in the text l0 2. Survey stations and study area t2 3. Distribution of anchovy eggs by cruises, 197 4-7 5 and I 975-76 t.t- I 5 4. Numbers of ancÌíovy eggs within the study area, lg74-75 and 1975-76 l5 5. Distribution of anchorry laruae by cruises, I 974-75 and I 975-76 . l6 6 Distribution of pilchard eggs,4-8 November 1974 t7 7. Distribution of pilchard larvae by cruises, 1974-75 and 1975-76 ... l8 8. Numbers of pilchard larvae taken by cruises, 197 4-7 5 and I 975-76 t9 9. Cumulative distribution of sprat eggs, 1974-75 and 1975-76 l9 10. Moray eel eggs l9 I I . Cumulative distribution of moray eel eggs, 197 4-7 5 20 12. Morayeellarva ... 20 I 3. Distribution of ahuru eggs by cruises, 197 +-7 5 and I 975-76 21 14. Numbers of ahuru eggs taken by cruises, 1974-75 and 1975-76 22 15. Ahu¡u larvae .. 22 16. Numbers of ahuru larvae taken by cruises, 1974-75 and 1975-76 I 7. Distribution of ahuru lawae by cruises, 1974-75 and 1975-76 23-24 18. Garfish larva 2+ 19. Roughylarva 2+ 20. Cumulative distribution of red gurnard eggs,197+-75 and 1975-76 21. Numbers of red gurnard eggs within the study area,1974-75 and 1975-76 2s 22. Cumulative distribution of red gurnard law¿e, 197 4-7 5 and I 975-76 25 23. Rockfish larva 26 24. Cumulative distribution of rockfish larvae, 1974-75 and 1975-76... 26 25. Jack mackerel Trachuns noaae4landiae eggs 27 26. Distributionof jackmackerelT.noue¿elandiaøeggsbycruises, 1974-75and 1975-76 ... 28 27. Numbers of jack mackerel T. noaaezelandia¿ eggs within the study area, 1974-75 and 1975-76 29 28. Jack mackerel T. noaa¿zelandia¿lawae 29 29. Distributionof jackmackerelT.nooaez¿lundiaelaruaebycruises, 1974-75 and 1975-76 30 30. Numbers of jack mackerel T. noaaezelandia¿lawae taken by cruises , I97 4-7 5 and I 975-76 3t 3 I Eggs of jack mackerel Trachutas decliuis 3l 32. Cumulative distribution of jack mackerel T. declitis eggs,1974-75 and 1975-76 J1 33. Snapper lawae 32 34. Distribution of snapper larvae by cruises, 197 4-7 5 and 197 5-7 6 .. JJ 35. Numbers of snapper laruae taken by cruises, Ì97,[-75 and 1975-76 5+ 36. Yellow-eyed mullet egg 34 37. Cumulative distribution o{ yellow-eyed mullet eggs, 1974-75 anð 1975-76 5f, 35 38. Yellow-eyed mullet larva .. Page 39. Spotty lawa 35 ,10. Spotted stargazer eggs 36 41. Cumulative distribution of spotted stargazer eggs, 197,1-75 and 1975-76 36 42. Spotted stargazer larvae JI 43. Cumulative distribution of spotted stargazer larvae, 197 4-7 5 and I 975-76 ... .14. Graham's gudgeon larvae 45. Cumulative distribution of Graham's gudgeon laruae,.1974-75 and 1975-76 39 46. Blue mackerel egg 39 47. Numbe¡s of blue mackerel eggs taken by cruises, 1974-75 39 48. Distribution of blue macke¡el eggs by cruises, I97,t-75 and t97 5-76 +0 49. Blue mackerel laruae 4l 50. Numbers of blue mackerel larvae taken by cruises, 1974-75 and 1975-76 +1 51. Distribution of blue macke rel laruae by cruises, 1974-75 and 1975-76 42 52. Crested flounder eggs +3 53. Cumulative distriburion of crested flounder eggs, 1974-75 +3 54. Crested flounder larvae ++ 55. Distribution of crested flounder laruae by cruises, lg7+-75 and 1975-76 +5 56. Distribution of pleuronectid eggs by cruises, 197+-75 and 1975-76 +G-47 57. Numbers of pleuronectid eggs taken by cruises, lg7+-75 and 19?5-76 +8 58 Flounder lawa +8 59. Cumulative distribution ol flounder laruae, 1974-75 znd 197:_76... 48 60. Numbers of flounder larvae raken by cruises, 1974-75 and 1975-76 49 6l . Speckled sole larvae 49 62. Cumulative distribution of speckled soìe larvae, lg74-75 and lg75-76 50 63. Numbers of speckled sole laruae taken by cruises, 1974-75 and 1975-76 50 64. Leather jacket eggs 50 65. Numbers o{ leather jacket eggs within the study area, lg74-75 and 1975-76 50 66 Distribution of leather jacket eggs by cruises, 1974-75 and 1975-76 5 r-52 67. Leather jacket larvae 53 68. Cumulative distribution of leatherjacket lawae,1974-75 and 1975-76 )+ 69. Unidentified egg I 54 70. Unidentified egg 2 55 71. Unidentified egg 3 55 72. Numbers of eggs of all species taken by cruises, 1974-75 and 197i:-16 57 73. Monthly cumulative wind speed from obseruations at Tiritiri Matangi Island 58 TABLES Page I . I(nds of eggs and larvae collected in the Hauraki Gulf . .. 2. Spawning season and remperarures for the principal species in the Hauraki Gulf 56 3. Comparative eggproduction for 1974-75and 1975-76 ... 57 Inset I 175"E 3ó"S Little Greot Borrier I Omoho Boy Colvílle chonn-l I .#--th*"wouärr( Cope Colville / 30 Tiririri \Motongi^ I Rokino ,0 " .', Firth of Thomes Fig. l:The Hauraki Gull, showing places mentioned in the text' INTRODUCTION The Hauraki Gulf, New Zealand's richest fishing There are few published accounts of ichthyoplank- ground, is a large, relatively shallow embayment with ton surveys from New Zealand. In the Hauraki Gulf many islands and harbours (Fig. l). It is an Cassie (t956a) studied the distribution of snapper important spawning ground for many fish species, eggs, and Colman (1973) studied the spawning of two including snapper (Chrysophrys auratus), which domi- species of flounder. Baker (1972) surveyed pilchard nates the commercial landings. During the spring- eggs and larvae in Tasman Bay, Robertson (ì980) summer periods (October to January) oÍ 1974-75 and recorded the distribution of the eggs of 17 species off 1975-76,2-weekly plankton surveys were carried out the Otago coast, and Colman (1979) studied the with the aim of estimating the stock size of snapper spawning of the sprat around the South Island. based on egg counts (Crossland 1980). These surveys Additional information on the eggs and larvae of were specifically designed for sampling snapper eggs; species mentioned in this bulletin is given in Elder however, many types of fish eggs and larvae were (1966), Robertson and Raj (1971), Baker (1973), collected, identified, and counted. These data are Robertson (1973), Castle and RÒbertson (1974), and presented in this bulletin. James (1976). Robertson's (1975) key describes the planktonic eggs of 56 species of New Zealand fishes. MATERIAL AND METHODS SAMPLING AND SORTING and larvae and sorted them according to type. When the sorters were sufficiently experienced to identify the Plankton samples were taken by oblique tows of a different kinds accurately, the common ones were cylinder-cone net at the stations shown in Fig. 2. counted in situ in the samples. Regular checks were Details of the net were: mouth area0.25 m2; cylinder made on the accuracy of identifications and sample 56 cm diameter by 150 cm long; cone slope length counts. Large samples were divided with a Folsom 185 cm; gauze 0.425-mm aperture with a porosity of splitter until a manageable fraction was obtained. In 47"/.. Ttie total filtering area was 2.225 m2 and the samples where eggs were abundant but larvae were filtering'area/mouth area ratio was 8.9, made up of not, eggs were subsampled, and the whole sample was 5.35 in the cylinder a¡rd 3.55 in the cone.