Topic
Harriotta
About: Harriotta is a research topic. Over the lifetime, 21 publications have been published within this topic receiving 160 citations.
Papers
TL;DR: Generalised additive models indicated that depth was the most important spatial predictor of research trawl survey catch rates, and depth separation was most pronounced between H. raleighana and H. novaezealandiae.
Abstract: The diets of Harriotta raleighana, Hydrolagus bemisi and Hydrolagus novaezealandiae were determined from examination of digestive tract contents from specimens sampled at depths of 219 to 876 m on the submarine ridge, Chatham Rise, New Zealand. All 3 species fed predominantly on benthic epifauna and infauna. Similarity percentages indicated the diet of H. raleighana was characterised by polychaetes and molluscs, H. bemisi by crabs and polychaetes, and H. novaezealandiae by crabs and sea urchins. Multivariate analyses using distance-based linear models found the most important predictors of diet variability were a categorical predictor for the subtropical front (STF) and bottom temperature. Cluster analysis of species subgroups indicated there was a greater similarity in diet between H. raleighana and H. bemisi, and between H. bemisi and H. novaezealandiae, in similar locations, than between subgroups of H. bemisi in different locations. Generalised additive models indicated that depth was the most important spatial predictor of research trawl survey catch rates, and depth separation was most pronounced between H. raleighana and H. novaezealandiae. Other significant predictors of diet variability included longitude, and fish length or weight. In all 3 species the diet of smaller fish included more polychaetes, small crustaceans and gastropods, and the diet of larger fish contained more decapod crustaceans. The primary factor determining niche separation among the 3 species appears to be depth and distribution rather than dietary specialisation.
35 citations
TL;DR: The results indicate that the traditional morphological generic definition of the families Rhinochimaeridae and Chimaera has to be reinvestigated and the time of origin of extant holocephalan taxa is provided.
29 citations
1 Feb 2017
TL;DR: Sexual dimorphism in snout length was found in H. raleighana, where male relative snout size increased at sexual maturity, suggesting the snout is a secondary sexual characteristic.
Abstract: The family Rhinochimaeridae, the long-nose chimaerids, consists of eight species across three genera, two of which occur in New Zealand waters. Very little is known about the biology of the rhinochimaerids. Longnose spookfish, ( Harriotta raleighana , Goode and Bean, 1895 ), and Pacific spookfish, ( Rhinochimaera pacifica, Mitsukuri, 1895 ), were collected from research trawl surveys and by commercial fishing vessels around New Zealand at depths between 400 and 1300 m. A total of 300 H. raleighana were caught which varied in length from 18.7 to 90.4 cm chimaera length (CL), and 168 R. pacifica at lengths of 20.9–139.9 cm CL. External assessment of male claspers and female gonad mass and oviducal gland width were the best indicators for maturity. Both species matured at a large proportion of their maximum length. Length at maturity was estimated at 62.8 cm CL and 75.8 cm CL for male and female H. raleighana respectively, and 105.3 cm CL and 125.0 cm CL for male and female R. pacifica . Fecundity was low and measured up to 27 eggs for H. raleighana, and 31 eggs for R. pacifica . Sperm storage was confirmed in females of both species. Sexual dimorphism in snout length was found in H. raleighana , where male relative snout size increased at sexual maturity, suggesting the snout is a secondary sexual characteristic. This study contributes to a better understanding of the life histories of H. raleighana and R. pacifica and their vulnerability to exploitation as fisheries bycatch.
19 citations
1 Sep 2007
TL;DR: High infestation of Gyrocotyle affected the chimaeroid species, increasing with depth, and narrownose chimaera had a greater number of parasites per host, and bigger individuals were more affected, while black dogfish showed a clear increase of HSI with the body weight, while chimaers presented a bigger variation.
Abstract: Feeding habits and biological features of three deep-water species -large-eyed rabbitfish (Hydrolagus mirabilis), narrownose chimaera (Harriotta raleighana) and black dogfish (Centroscyllium fabricii)distributed in the Grand Bank and Flemish Cap (Northwest Atlantic) were analyzed. Both chimaeroid species fed on endo and epi-benthic organisms, but with different behavior. Narrownose chimaera showed a closer relationship with the sea bed in the feeding habits, denoted mainly by the high polychaete and sediment presence; while in large-eyed rabbitfish, the great importance of pelagic prey (Coryphaenoides rupestris and cephalopods) would indicate wider feeding habits, increased with the predator size. Black dogfish preyed mostly on pelagic and benhopelagic prey (crustaceans, scyphozoans and fish). High infestation of Gyrocotyle affected the chimaeroid species, increasing with depth. The parasitation affected 67% of large-eyed rabbitfish, with higher percentage for smaller individuals; narrownose chimaera (84% with parasites) had a greater number of parasites per host, and bigger individuals were more affected. However, presence of Gyrocotyle did not seem to harm the well-being of the specimens. Length-weight relationship indicated bigger body weight for males in the small sizes of 108, 31.5 and 50 cm of large-eyed rabbitfish, narrownose chimaera and black dogfish respectively. However, the body-eviscerated weigh relationship did not show differences between sexes. The hepatosomatic index (HIS) was high in all species, mainly in narrownose chimaera (31.3%) and it reached in the other species a value around the fourth part of their eviscerated weight. Black dogfish showed a clear increase of HSI with the body weight, while chimaerids presented a bigger variation.
12 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
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| 2021 | 1 |
| 2020 | 1 |
| 2019 | 1 |
| 2017 | 1 |
| 2016 | 1 |
| 2014 | 2 |