Topic
Ipnops
About: Ipnops is a research topic. Over the lifetime, 4 publications have been published within this topic receiving 23 citations. The topic is also known as: grideye fish.
Papers
TL;DR: There is the possibility of northward transport during a long larval stage by the prevailing Kuroshio Current from its typical adult habitat in the subtropical/tropical western Pacific.
Abstract: During a dive of the submersible Shinkai 6500 (run by the Japan Agency for Marine-Earth Science and Technology, JAMSTEC, formerly the Japan Marine Science and Technology Center) in the Japan Trench, off Cape Erimo, northern Japan, the second author succeeded in taking a photograph of an ipnopid fish on the bottom at about 3,500 m (Fig. 1). Locality data are as follows: Okamura (Cadet) Seamount (41 15.960N, 144 34.560E), water temperature 1.8 C, at the apex of the seamount, KY07-14, mother ship Yokosuka, 1 October 2007. This specimen was readily referred to the genus Ipnops based on its general morphology and the distinctive reflection of light from its unique plate-like eyes, as finely demonstrated in the robotic-camera photograph of Roper and Brundage (1972). This record represents an unexpected northern extension of the geographical ranges of the genus, including its first appearance in Japanese waters. Currently two species of Ipnops are known from lower bathyal and abyssal depths in the Indo-Pacific Ocean, i.e., Ipnops agassizi and Ipnops meadi. The two species can usually be separated by their depth of capture, with I. agassizi found at shallower depths than I. meadi at the same latitude (Fig. 2). Ipnops agassizi is concentrated in the lower bathyal zone (\3,000 m) north of around 20 S, whereas I. meadi occupies a deeper habitat and extends its depth range to the abyssal zone (down to 5,400 m; Shcherbachev 1981) further south, in the absence of I. meadi. In contrast, I. meadi is restricted to the abyssal zone (3,310–4,940 m) throughout its range. From these data, the present specimen is most probably referable to I. meadi, and represents an extension of its northern range limit from ca. 29 N to ca. 41 N. The size of this specimen is estimated to be about 150 mm in TL from the photograph taken from the submersible, which was more than 5 m from the target fish. Since recorded demersal specimens of I. meadi are 50–121 mm SL (Nielsen 1966), this fish may be a fully grown adult. Judging from the photograph, this true benthic fish inhabits a slightly disturbed muddy flat bottom (also confirmed on the core sample near the present photo site) dominated by certain ophiuroids. Although little is known about the biology of I. meadi, the putative early life history of I. agassizi, including extensive ontogenetic vertical migration terminating at around 55 mm SL (Okiyama 1986, 1988), may be shared by I. meadi. In the present case, therefore, there is the possibility of northward transport during a long larval stage by the prevailing Kuroshio Current from its typical adult habitat in the subtropical/tropical western Pacific. Without the specimen to hand, it is also possible that an undescribed species is represented in the photograph. M. Okiyama (&) Marine Ecology Research Institute, Towa Edogawabashi Bldg 7F, 347 Yamabuki, Shinjyuku-ku, Tokyo 162-0801, Japan e-mail: okiyama@kaiseiken.or.jp
2 citations
TL;DR: The osteological description of the ocular head region and the pectoral girdle of Ipnops agassizii Garman, 1899 (family Ipnopidae) was made based on material collected from bathyal and ultra-abyssal depths and features of the fin skeleton are analyzed.
Abstract: The osteological description of the ocular head region and the pectoral girdle (using alizarin-stained preparations) of Ipnops agassizii Garman, 1899 (family Ipnopidae) was made based on material collected from bathyal and ultra-abyssal depths (3020–5410 m). A detailed description of the axial skeleton is provided and features of the fin skeleton are analyzed (using X-ray images). The morphological transformations in the skeleton that occurred as a result of living at great depths are considered. The wide range of functional and morphological specializations, which have an adaptive pattern aimed at adaptation to deep-sea habitats in contact with the bottom, are shown. The fin rays of the unpaired fins and their supporting elements (respectively, interneuralia and interhaemalia) have reinforced bony heads. The pelvic fins are located at the vertical line through the tips of the pectoral fin rays, slightly anteriorly of the mid-body level. The dorsal fin is located far anteriorly of the anal fin. The caudal peduncle is equally flattened both laterally and dorsoventrally.
TL;DR: A new crangonid genus is established for an unusual new species, P. formosa, which is described on the basis of material from off Taiwan in the northwestern Pacific, with a large and reflective plate-like eye that is unknown in decapod crustaceans before but similar to the eyes of the deep-sea grideye fish of the genus Ipnops Günther.
Abstract: A new crangonid genus, Placopsicrangon, is established for an unusual new species, P. formosa, which is described on the basis of material from off Taiwan in the northwestern Pacific, at the abyssal depths of 4412-4824 m. This new genus has a large and reflective plate-like eye that is unknown in decapod crustaceans before but similar to the eyes of the deep-sea grideye fish of the genus Ipnops Gunther, 1878. The new genus is also unique within Crangonidae by having a laterally compressed rostrum with dentate dorsal margin, and the presence of a transverse row of sharp teeth adjacent to the posteroventral margin of the sixth pleonal sternite. Placopsicrangon appears closest to Sabinea in the general pattern of the carination on the carapace and pleon, and the substantially reduced non-chelate second pereiopod. This new taxon is the sixth representative of Crangonidae inhabiting the abyssal zone.
TL;DR: In this article, the authors used towed camera transects and baited camera data (1989-1992) to evaluate the fish community at the DISCOL site and found that the abyssal fish community included 16 taxa and was dominated by Ipnops meadi.
Abstract: . Industrial interest in deep-sea mineral extraction began decades ago, and
today it is at an all-time high, accelerated by global demand for metals.
Several seafloor ecosystem disturbance experiments began in the 1970s,
including the Disturbance and Recolonization experiment (DISCOL) conducted
in the Peru Basin in 1989. A large seafloor disturbance was created by
repeatedly ploughing the seafloor over an area of ∼10.8 km 2 . Though a number of studies in abyssal mining regions have
evaluated megafaunal biodiversity and ecosystem responses, few have included
quantitative and detailed data on fishes or scavengers despite their
ecological importance as top predators. We used towed camera transects
(1989–1996, 2015) and baited camera data (1989–1992) to evaluate the fish
community at the DISCOL site. The abyssal fish community included 16 taxa
and was dominated by Ipnops meadi. Fish density was lower in ploughed habitat at 6 months and 3 years following disturbance but thereafter increased over time.
Twenty-six years after disturbance there were no differences in overall total
fish densities between reference and experimental areas, but the dominant
fish, I. meadi, still exhibited much lower densities in ploughed habitat, likely
avoiding these areas and suggesting that the fish community remains affected
after decades. At the scale of industrial mining, these results could
translate to population-level effects. The scavenging community was
dominated by eelpouts (Pachycara spp.), hermit crabs (Probeebei mirabilis) and shrimp. The large
contribution of hermit crabs appears to be unique amongst abyssal scavenger
studies worldwide. The abyssal fish community at DISCOL was similar to that
in the more northerly Clarion–Clipperton Zone (CCZ), though some species have only
been observed at DISCOL thus far. Also, further species-level
identifications are required to refine this assessment. Additional studies
across the polymetallic nodule provinces of the Pacific are required to
further evaluate the environmental drivers of fish density, diversity and
species biogeographies. This information will be important for the
development of appropriate management plans aimed at minimizing human impact
from deep-sea mining.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 1 |
| 2010 | 1 |
| 2009 | 1 |