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Description of a new* Coelorinchus*(Macrouridae, Gadiformes, Teleostei) from Taiwan, with notable new records of grenadiers from the South China Sea
Abstract and Figures
Among recent collections of grenadiers procured from fishery ports in northeastern Taiwan were ten specimens of an undescribed species of Coelorinchus, which we here describe as C. fuscigulus sp. nov. One of the specimens was recorded previously as C. cylindricus Iwamoto and Merrett, 1997, but that species differs from the new species most notably in having a complete bony support of the anterolateral snout margin, compared with margin incompletely supported. Other differences include proportional measurements (preoral length, orbit diameter, distance orbit to preopercle, postorbital length of head, length of upper jaw, and body depth), scale row counts, and body markings. Three other species (Coryphaenoides asper, Coelorinchus spinifer, Kumba gymnorhynchus) recently collected by deepwater trawls in the South China Sea are the second records for the species; specimen data are provided for these species.
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... Record from off northeastern Taiwan (Shao et al. 2008) is a misidentification of C. fuscigulus (Iwamoto et al. 2009). Allied to C. hubbsi group but with anterolateral margins of snout completely supported by bone. ...
... cylindricus Iwamoto &Merrett, 1997, have the snout completely supported by bone, though other characters agree well with members of the C. hubbsi group. Okamura (1984), Chiou et al. (2004), Iwamoto et al. (2009) andProkofiev (2021) included C. acutirostris in this assemblage while Nakayama et al. (2020) did not. The new species is characterized by the snout incompletely supported by bone and the second dorsal fin as high as anal fin; thus, it belongs to the C. hubbsi group in its strict sense. ...
... The new species agrees with C. cingulatus, C. fuscigulus Iwamoto, Ho & Shao, 2009, C. melanosagmatus, C. multifasciatus Sazonov & Iwamoto, 1992and C. spilonotus Sazonov & Iwamoto, 1992 in the banded pattern with no isolated suprapectoral blotch. Coelorinchus ganymedes Prokofiev, 2021, C. gladius Gilbert & Cramer, 1897and C. matsubarai Okamura, 1982 from the northwestern and central Pacific can be distinguished from the aforementioned species in possessing a completely separated, conspicuous rounded blotch on flank between the lateral line and the pectoral-fin base. ...
A new species, Coelorinchus tricristiger sp. nov., is described from the western Indian Ocean off Socotra and Somalia. It belongs to the Coelorinchus hubbsi group of the subgenus Quincuncia. The modified scales on top of the postorbital portion of head forming a prolonged longitudinal ridge, in combination with its distinctive body markings and the absence of a ventral projection of subopercle, make the new species easily distinguishable from congeners. This is the second representative of the C. hubbsi group in the western Indian Ocean in addition to the previously known C. melanosagmatus.
... the suborder Gobioidea ( gobies and allies ) . Tomio Iwamoto , a world expert on deep - sea fishes and the first author ( W . N . E . ) have identified areas where more work is needed , especially the Indian Ocean , deep - sea ridges and seamounts , and in deep water generally ( mostly in the Southern Hemisphere ) . A statement in a recent paper ( Iwamoto et al . 2009 : 47 ) noted , " The recent captures in more than 3 , 000 m off Japan , … are additional examples of this lack of adequate collecting at greater ocean depths . " Grenadiers ( Macrouridae ) are Iwamoto ' s specialty , and he and co - workers have described 93 species in the last 39 years ( through 2009 ) ; 390 species are currently recog ...
The increase in knowledge of marine fish biodiversity over the last 250 years is assessed. The Catalog of Fishes database (http://research.calacademy.org/ichthyology/catalog) on which this study is based, has been maintained for 25 years and includes information on more than 50,000 available species names of fishes, with more than 31,000 of them currently regarded as valid species. New marine species are being described at a rate of about 100–150 per year, with freshwater numbers slightly higher. In addition, over 10,000 generic names are available ones of which 3,118 are deemed valid for marine fishes (as of Feb. 19, 2010). This report concentrates on fishes with at least some stage of their life cycle in the sea. The number of valid marine species, about 16,764 (Feb. 19, 2010), is about equal to that of freshwater fishes (15,170). Valid species of fishes apparently restricted to brackish water number only 108. The sum (32,042) is more than the current total number of 31,362, valid species of fishes because some species occur in more than one habitat. Presented is information on the description of species and genera over historic time, the authors describing taxa, and the deemed validity of described species and genera. We characterize families and also geographic areas where marine fishes are relatively well known and those where much discovery appears to remain. Endemism is also discussed. As examples, the marine fish faunas of the Mediterranean Sea, the Red Sea and the Mascarene Islands are shown to be well known. Little new discovery has been found recently at the family level, and new discoveries of species and genera are mostly limited to certain families and geographic areas and habitats. Specialized collecting techniques are discussed. Overall success rates for valid species discovery through time has only been about 50%, or two species described for each valid one recognized; however this percentage has been improving over time. Because of recent improvements in technology, literature availability, quality of analysis, better communication, and other factors, the current success rate for validity of species is well over 90% (with a small lag time as status is confirmed or rejected by the ichthyological community). Two habitats where most new marine taxa will likely be found are deep-reefs and deep-slopes, areas poorly sampled and studied. Some deep-sea areas, particularly in the Southern Hemisphere and throughout the Indian Ocean and in Indonesia, should reveal many new taxa from increased collecting efforts. Molecular genetic studies are proving valuable in phylogenetic and phylogeographic analyses as well as in species' population analyses, but these relatively new techniques are not uncovering large numbers of new or cryptic taxa. An estimate of marine fish species yet to be sampled and described is about 5,000, or twice the number described in the last 19 years, for a projected total of approximately 21,800 valid marine species of fishes.
A new species of grenadier, Coelorinchus posteromaculatus, is described from nine specimens collected from the tropical eastern Indian Ocean at depths of 100–323 m. This species belongs to the Coelorinchus argentatus group (defined here to include 13 species), but differs from other members of that group in its unique body markings consisting of a single, prominent, lateral, dark blotch on the anterior part of the tail, and a slightly diagonal, narrow, dark stripe extending from the upper margin of the gill opening to below the first dorsal-fin midbase or beyond. Coelorinchus posteromaculatus is most similar to C. gaesorhynchus Iwamoto and Williams 1999 and C. longissimus Matsubara 1943, but further differs from the former in its much shorter snout (74–91% of postrostral length vs. 93–100% in C. gaesorhynchus), and from the latter in its relatively small mouth (upper-jaw length 38–43% of postrostral length vs. 42–49%).
An annotated checklist of fish genera and species described from Taiwanese waters through 2009 is presented. It includes 20 genera and 336 species/subspecies in 99 families. Of these, 225 species/subspecies are currently recognized as valid and 111 are invalid, including 7 questionable species. The current status of each taxon, if different from that of the original description, is provided. Thus far, 41 primary freshwater and estuarine species/subspecies are considered as endemic and 55 marine species are found only around Taiwan. The type series collected from Taiwan are also listed based on the information provided in the original descriptions and from our investigation. It includes approximately 2217 specimens in 779 lots, including 242 holotypes and lectotypes, 5 neotypes, 35 lots of syntypes and 497 lots of paratypes and paralectotypes. There are still 19 species lacking primary types and 11 lots with at least 31 unknown secondary type specimens.
The study of deep-sea fish fauna is hampered by a lack of data due to the difficulty and high cost incurred in its surveys and collections. Taiwan is situated along the edge of the Eurasia fig, at the junction of three Large Marine Ecosystems or Ecoregions of the East China Sea, South China Sea and the Philippines. As nearly two-thirds of its surrounding marine ecosystems are deep-sea environments, Taiwan is expected to hold a rich diversity of deep-sea fish. However, in the past, no research vessels were employed to collect fish data on site. Only specimens, caught by bottom trawl fishing in the waters hundreds of meters deep and missing precise locality information, were collected from Dasi and Donggang fishing harbors. Began in 2001, with the support of National Science Council, research vessels were made available to take on the task of systematically collecting deep-sea fish specimens and occurrence records in the waters surrounding Taiwan. By the end of 2006, a total of 3,653 specimens, belonging to 26 orders, 88 families, 198 genera and 366 species, were collected in addition to data such as sampling site geographical coordinates and water depth, and fish body length and weight. The information, all accessible from the "Database of Taiwan's Deep-Sea Fauna and Its Distribution (http://deepsea.biodiv.tw/)" as part of the "Fish Database of Taiwan," can benefit the study of temporal and spatial changes in distribution and abundance of fish fauna in the context of global deep-sea biodiversity.
A new grenadier, Nezumia shinoharai, is described based on two specimens collected from the continental slope off the Pacific coast of southern Japan, at depths of 627–700 m. The new species is clearly distinguished from all other congeners by the following combination of characters: pelvic fin rays 10; spinules on body scales needlelike, arranged in discrete parallel rows; underside of head almost completely naked with prominent sensory pores; teeth in broad cardiform bands in both jaws; snout long (31–34% HL), conically pointed, protruding well beyond upper jaw; first dorsal fin uniformly dark with pale distal tip, second spinous ray not extremely elongated (height of first dorsal fin about equal to HL); no dark band encircling trunk.
Caelorinchus melanosagmatus n. sp. is newly described from upper continental slope waters of the Indian Ocean off Tanzania, Kenya, and in the Andaman Sea. The distinctive banding pattern on the body in combination with a high second dorsal fin, slender snout with terminal scute elongated and sharp, and naked underside of head, among other features, distinguish the new species from all others of the genus. It is most similar to two Pacific species C. cingulatus and C. spilonotus, but the three species differ in details of the banding pattern, and C. spilonotus differs also in pyloric caeca count. The disjunct distribution of the new species, with its apparent absence in the Arabian Sea and Bay of Bengal, is perplexing. The number of currently recognized grenadier species from the Indian Ocean is 114, but many more are known and yet to be described.
