The life history of Galaxias vulgaris Stokell,with a comparison with G. maculatus attenuatus

Galaxias vulgaris Stokell is a totally freshwater fish species and the adults usually live a cryptic life under stones. The life history of this species, with special emphasis on its embryology, growth rate, and sex ratio, is described. Comparisons are made with other members of the family Galaxiidae, especially G. maculatus attenuatus     

A consideration of the whitebait stage of Galaxias maculatus attenuatus (Jenyns)

The size composition of a season's catch of Galaxias maculatus attenuatus (Jenyns) whitebait is given. An analysis of consecutive catches shows that there is no overall increase in the size of the whitebait caught. This supports the theory that these fish have reached a physiological stage at which they migrate up accessible freshwater streams. The subsequent changes are so great that they warrant the term metamorphosis.

The whitebait stages of other species of Galaxias are briefly compared.     

缢蛏(Sinonovacula constricta)微卫星标记的分离及近缘物种通用性

采用磁珠富集和PCR筛选相结合的方法,得到12对缢蛏(Sinonovacula constricta)的多态性微卫星引物。每个位点的观测等位基因数为2—15个,有效等位基因数为1.0339—8.8063个;观测杂合度(Ho)为0.0333—1.0000,平均观测杂合度为0.7525;期望杂合度(He)为0.0333—0.9020,平均期望杂合度为0.6866;多态信息含量(PIC)为0.0320—0.8680。所有位点中,有8个位点属于高度多态位点(PIC0.5),SC1-5和SC4-6属于低度多态位点(PIC0.25);经Bonferroni校正后,无显著偏离哈迪-温伯格平衡的位点;连锁不平衡检验结果表明,位点间不存在连锁不平衡现象。此外,分析了这些引物在近缘种长竹蛏(Solen strictus)、大竹蛏(Solen grandis)和小刀蛏(Cultellus attenuatus)的通用性情况,结果显示:长竹蛏中,位点SC1-4、SC2-8、SC3-1、SC3-14表现出了高度多态(PIC0.5);在大竹蛏中,位点SC3-4、SC3-7、SC4-6表现出了高度多态性(PIC0.5),SC2-9为低态位点(PIC0.25);在小刀蛏中,位点SC1-7、SC2-9、SC3-4、SC3-14表现出了高度多态性(PIC0.5),SC4-6为低态位点(PIC0.25)。     

Life‐history studies on New Zealand Brachyura

A brief account is given of the systematics and distribution of Heterozius rotundifrons A. Milne Edwards, Ozius truncatus H. Milne Edwards, and Heteropanope (Pilumnopeus) serratijrons (Kinahan). Keys are given for the separation of Zoea larvae of New Zealand xanthid Brachyura and to the Megalopa larvae of Heterozius rotundifrons and Ozius truncatus

Notes are given on the seasonal breeding cycle of Heterozius rotundifrons, and the pre‐Zoea larva, two Zoea larval stages, and Megalopa larva reared in the laboratory are described. Larval characters of H. rotundifrons are specialised and do not support its recently suggested classification in the family Atelecyclidae. The larvae show no relationships with those of the Cancridae or of the Corystidae, and affinities with described larvae of the Xanthidae or even the Brachyrhyncha are obscure. Larval development is incompletely abbreviated possibly to reduce dispersal in response to restricted intertidal habitat requirements of the adult crabs.

The pre‐Zoea larva, four Zoea larval stages, and the Megalopa larva of Ozius truncatus reared in the laboratory are described. A key to the Zoea larval stages is given. Larvae of this species are distinct both at the generic and specific levels, but are generally similar to those known of xanthid crabs. It is difficult to relate the genus Ozius to other xanthid genera on the basis of larval characters alone.

The pre‐Zoea larva and stage one Zoea larva of Heteropanope (Pilumnopeus) serratifrons are described. There are probably four Zoea larval stages in the development of this species. Zoea larval characters suggest that in the family Xanthidae, Heteropanope and Pilumnopeus should be separated from other genera in the subfamily Pilumninae with which they are currently classified.     

Life‐history studies on New Zealand Brachyura

Abbreviated or direct development is described in Pilumnus novaezealandiae Filhol, 1886 and P. lumpinus Bennett, 1964 from New Zealand. Embryonic development is separated into Nauplius, Metanauplius and embryonic zoeal stages. The ontogenetic position of the pre‐zoeal cuticle suggests that it represents the Metanauplius stage, and the absence of plumose pre‐zoeal aesthaetes in P. novaezealandiae implies relationship with the more recently evolved brachyuran families. The significance of the pre‐zoeal cuticle in brachyuran phylogeny is discussed. In P. noveazealandiae four embryonic zoeal phases are recognised as approximately equivalent to the four Zoea larval stages occurring in the majority of xanthid Brachyura. It was not possible to distinguish similar phases in embryonic zoeal development of P. lumpinus because of advanced anachronism which is normally associated with abbreviated development. The appearance of relatively advanced structures very early in ontogeny is attributed to the absence of the need for successive developmental stages to be adapted for free life. In the embryonic Zoea, carapace spines considered to assist with flotation and orientation, and natatory setae, are together reduced or absent in abbreviated development where such structures would be of no use within the egg.

In P. novaezealandiae and P. lumpinus increase in egg size during incubation is probably due to absorption of water by the embryo during development, and eclosion is initiated by rupture of the chorion through internal pressure thus created. Larvae of P. noveazealandiae hatch at a Megalopa larval stage and are retained beneath the pleon of the female crab. Those of P. lumpinus hatch as advanced, much‐modified, and non‐natatory Zoeae which are not retained by the parent. Simultaneous moulting of the pre‐zoeal and zoeal skins occurs in both species.

The Megalopa larva and first five juvenile crab stages of P. novaezealandiae are described and compared with equivalent stages of P. vestitus from Australia recorded by Hale (1931). The Megalopa larva of P. lumpinus is described. P. lumpinus is considered as the least evolved of the three species of Pilumnus possessing abbreviated development, while P. vestitus suggests a second stage, and the third and most advanced stage is shown by P. novaezealandiae Ecology of these three species is correlated with abbreviated development. Retention of potentially free‐swimming Megalopa larvae by the parent explains gregariousness among juvenile crabs and adults of both P. novaezealandiae and P. vestitus

It is probable that abbreviated development has evolved among marine and freshwater Brachyura as a response to habitat requirements of the adult crabs. Partial or complete abbreviation of the planktonic phase and retention of larvae would assist with retaining the stock within a restricted locality or ecological niche. Abbreviated development among Brachyura therefore has little phylogenetic significance.     

Larval stages,developmental ecology,and distribution of Scyllarus sp. Z (probably Scyllarus aoteanus Powell, 1949) (Decapoda: Scyllaridae)

Phyllosomata and nistos of Scyllarus sp. Z taken from plankton around and offshore northern New Zealand and in the Tasman Sea are presumed to be those of S. aoteanus Powell, 1949, the most common Scyllarus species in this area. The full larval and postlarval development of this species are described. Three features are characteristic of Scyllarus sp. Z phyllosomata; a dorsal crest on the cephalic shield, dorsal thoracic spines, and a forked telson in middle stages persisting as two prominent spines outreaching the telson posterior margin in the final stage. Scyllarus sp. Z's closest affinities are with a group of Scyllarus species whose phyllosomata have forked telsons in middle stages and medium to strong posterolateral telson spines in the final stage. The nisto is low in profile but distinctive in its armature. Too few Scyllarus sp. nistos have been described to suggest any group to which that of Scyllarus sp. Z can be assigned. The spatial and temporal distribution of the larvae and postlarvae of Scyllarus sp. Z are also described. Although early larval stages and postlarvae are found close to New Zealand, mid‐ and late‐stage larvae are widely distributed, some well beyond the known latitudinal range of the adults. There is probably an extended egg‐bearing and hatching period as early stage larvae are caught in most months. Variable rates of development of the larvae and/or delayed metamorphosis, are also possible.     

中国经济头足类增养殖现状及展望

头足类(Cephalopods)是软体动物门的重要组成部分,在中国海洋渔业中占有重要的经济地位。开展头足类增养殖,对于保护中国种质资源、提高头足类产量具有重要意义。本文就目前中国主要的经济头足类,包括金乌贼(Sepia esculenta)、拟目乌贼(S.lycidas)、虎斑乌贼(S.pharaonis)、无针乌贼(Sepiella japonica)、长蛸(Octopus minor)、真蛸(O.vulgaris)以及短蛸(Amphioctopus fangsiao)的繁殖习性、幼体培育、成体养成等各阶段生活史的研究进展和存在问题进行阐述,并对其发展前景进行展望,旨在为中国头足类养殖产业提供借鉴。     

Early post-cleavage stages and abnormalities identified in the embryonic development of chokka squid eggs Loligo vulgaris reynaudii

Six early, post-cleavage embryonic stages for chokka squid Loligo vulgaris reynaudii eggs that were developed in an aquarium are identified and described, expanding the embryonic stages for this species from 14 to 20. The influence of water temperature on embryonic development is described. At temperatures <12 and >15°C, high percentages of morphological abnormalities were observed in embryonic development. Gross forms are described and illustrated.     

Laboratory culture of Galaxias maculatus and potential applications

Galaxias maculatus has considerable potential as a laboratory animal. Laboratory techniques used to maintain, artificially spawn, hatch, and rear this New Zealand native freshwater fish are described. Potential research applications for the fish, the eggs, and the larvae are outlined. The development of the larvae is described.     

New and little‐known species of Heterorhabdidae (Copepoda: Calanoida) from the southwest pacific

Three new species of calanoid copepods are described: two in Heterorhabdus and one in Disseta. The males of H. pustulifer and H. caribbeanensis are described and the identities of H. proximus, H. norvegicus and H. austrinus are clarified. H. spinifer is recorded for the second time. A key to the subgenus Heterorhabdus is provided.     

Comparative embryogenesis of Australian and South African viviparous clinid fishes (Blennioidei,Teleostei)

The study follows the embryogenesis of 16 species of viviparous clinid fishes (Clinidae, Teleostei), from the Cape south coast of South Africa and from Australia, with comparative remarks on the development of juveniles in oviparous species. The sperm intromitted into the female duct fertilise the eggs within the follicles. The embryos then develop in individual follicles, nourished by nutrients derived from the mother, until they are mature for release. During the reproductive season in the South African genera Clinus and Muraenoclinus, the female's ovaries harbour eggs and embryos at various stages of development, whereas in species of the Australian genera Heteroclinus and Cristiceps, most embryos in each ovary are at an approximately equal stage of development. The ovaries of the studied species fall into two groups: species of Heteroclinus and Cristiceps that produce numerous small eggs, and species of Clinus and Blennophis that produce fewer, larger eggs. As a consequence, Heteroclinus spp. and Cristiceps spp. bear and release high numbers of smaller embryos, of c. 10-13 mm long, whereas others (e.g. Clinus superciliosus, C. cottoides) bear fewer embryos, of up to 22 mm long. The organogenesis of various organs is described, with particular emphasis on chondrification and ossification. The onset of gut, sensory organ and skeletal development in Heteroclinus and related species occurs in embryos of 2.5-3.0 mm, whereas in Clinus spp. organ development starts in 5.0-6.0 mm embryos, and occurs in parallel both in the head capsule and at the caudal ends. Consequently, the pace of embryogenesis in the studied Australian small-egg species is faster in several aspects, and their embryos at the time of release are smaller than those of the large-egg species. The developmental sequences and related phenomena are discussed.     

Growth characteristics,pigmentation, and the identificaton of whitebait (galaxias spp., Salmonoidea)

Definitions are given for stages in the development of five species of Galaxias, family Galaxiidae, which have marine larvae.

Larvae of Galaxias maculates attenuates and G. brevipinnis are large, and those of G. fasciatus relatively small as they enter fresh water from the sea. Development as whitebait involves shrinkage by about 25% in total length; the head length, considered separately, shrinks by about 15%. The ratio of standard length to head length alters from the larval to the adult value before positive growth recommences. These features are probably similar for G. postvectis and G. argenteus

Minimum observed pigmentation is described for the late larvae of G m. attenuates, G. brevipinnis, and G. fasciatus and for early whitebait of these and of G. postvectis and G. argenteus Subsequent development of melanophores and of colour pattern is described and figured. Large melano‐phores along the lateral line distinguish early whitebait of G. m. attenuates, but no distinguishing feature of pigmentation has been found in other species until the juvenile pattern is apparent. This pattern is characteristic for each species, and it persists in adult G. m. attenuates. G. argenteus has distinct juvenile and adult patterns, the latter being developed in a second, superficial, layer of pigment cells. Adult G. postvectis develop a distinctive fin colour pattern unlike other New ‐Zealand Galaxias; the superficial pigment layer is without definite pattern. In adult G. brevipinnis this layer resembles the persistent juvenile pattern and the two layers combined give a reticulate appearance. In G. fasciatus the juvenile pattern persists and develops as the fish grow; the superficial pigment layer is present in adults but is not usually apparent.

Until now positive identification of whitebait has depended on colour pattern. Recently recorded identifications of unpigmented whitebait are shown to be misleading. A key is given for the identification of early and late whitebait using absolute measurements as an important character.     

法紫菜生物多样性及其栽培生物学基础

综述了重要经济红藻法紫菜属物种多样性及其地理分布,修订了法紫菜属中文名称,回顾了紫菜生活史研究的历程,基本概括了法紫菜栽培生物学基础研究成果。根据文献报道及最新研究成果,认为紫菜属和法紫菜属共有138个物种,集中分布在北半球的温带、亚热带海域,其中我国是物种多样性较高的国家之一,其物种及变种数达到25个。法紫菜生活史的阐明对紫菜栽培产业的发展具有奠基性的作用,其中我国藻类学家曾呈奎和张德瑞在法紫菜生活史研究中作出了重要的贡献,提出了壳孢子的概念,被广泛接受并沿用至今。壳孢子采苗和丝状体培养技术是发展紫菜栽培业的重要基础,丝状体生长发育及壳孢子形成的分子机制将是未来法紫菜生物学研究的重点和难点。尽管根据已发表的相关文献大致梳理了法紫菜相关生物学基础研究的成果,但限于篇幅对栽培生产中相关技术的优化、完善与推广以及新品种培育等均未作介绍。     

Larval development of Boccardia knoxi,a shell‐infesting spionid polychaete

Larvae of Boccardia knoxi (Rainer) were reared in the laboratory after dissection from brood capsules extracted from the outer shell and perio‐stracum of Cookia sulcata and Haliotis iris collected from Tasman Bay, New Zealand. All the eggs within each brood capsule developed into embryos. The dissected larvae had provisional setae and fed on phytoplankton. Larval development is described through to metamorphosis.     

Notes on two Neoleptonid bivalve molluscs

Within its range of variation, the small New Zealand bivalve, Notolepton antipodum (Filhol), includes two Recent and two fossil forms previously described as species. The animal is common around all New Zealand and some details of its ecology and habits are presented. The foot and mantle cavity of the living animal are described and its anatomy briefly outlined. The relationships of Notolepton to Neolepton are discussed.

Some details of the movements of the foot, mantle ciliation, and gross anatomy of Pachykellya minima Powell are described and its known distribution is extended from the Subantarctic to North Auckland.     

New Notodelphyidae (Copepoda: Cyclopoida) from New Zealand solitary ascidians

The male of Doropygus platylhorax Jones, 1974 and two new species of Doropygus (D. louisae and D. spinosus) are described and illustrated. The specimens of Doropygus described by Schellenberg (1922) as D. pulex are assigned to the new species D. louisae. Specimens of Ophioseides (Scolecimorpha) joubini described by Schellenberg (1922) have been re‐examined together with fresh material, and have been described as a new species, Ophioseides schellen‐bergi.     

Exploitation of Antarctic marine living resources: a brief history and a possible approach to managing the krill fishery

Four major phases in the exploitation of Antarctic marine living resources are identified and briefly described, viz. exploitation of seals, whales, finfish and krill Euphausia superba Dana. The pattern of exploitation has shifted from one group of resources to another. The recent efforts of the Commission for the Conservation of Antarctic Marine Living Resources are considered in relation to management of finfish exploitation and to the development of a scientifically based management plan for krill. Special emphasis is given to the data required for the effective management of the krill fishery, per se, given the current limited knowledge of the potential yield of the resource and in the face of uncertainty concerning key aspects of the species' biology/ecology. A recent South African initiative aimed at developing a practical management strategy for the Antarctic krill resource is described.     

Common bivalve larvae from New Zealand: Leptonacea

The late stage larvae of three erycinid bivalves (Mollusca: Pelecypoda: Leptonacea) taken from the brood chamber of the adult are described (Kellia cycladiformis, Lasaea rubra hinemoa, and L. maoria), and the provisionally identified late stage larva of the erycinid Arthritica bijurca taken from the plankton is described. Also, the D‐shaped larvae of the erycinid bivalves Kellia cycladiformis, Borniola reniformis, Arlhritica crassijormis, and A. bifurca taken from the parent brood chamber are described. The seasonal occurrence of each late stage larva in the plankton at the Bay of Islands (35° 15'S, 174° 10'E), Wellington Harbour (41° 16'S, 174° 51'E), and Raumati Beach (40° 56'S, 174° 58'E), New Zealand is described. Aspects of the reproductive cycles of Lasaea rubra hinemoa and Arthritica bifurca are presented.     

Mollusca from a recent coral community in Palliser bay,cook strait

From a trawling at 448–512 m in Palliser Bay, Cook Strait, New Zealand, molluscs associated with. Tertiary siltstone concretions and with a large colony of Goniocorella dumosa (Alcock) are listed. A juvenile Acesta, extremely tall and extremely broad forms of Emarginula striatula Quoy & Gaimard, and the animals of Stilifer neozelanica Dell and of Waipaoa marwicki Dell are described. Sculptifer, a new genus provisionally included in the Fossaridae, is proposed for Stilifer neozelanica. New species of Danilia and Pholadidea are described and their relationships discussed. Emarginula lophelia Beu, 1967 is synonymized with E. striatula Quoy & Gaimard, 1834, and the recent New Zealand forms of Emarginula are reviewed.