Stichaeid Fish Research Articles

Revision of the Scientific Name for "Min-be-do-ra-chi" Identified Previously as Zoarchias glaber in Korea

The Korean stichaeid fish “Min-be-do-ra-chi”, reported previously as Zoarchias glaber, is reviewed taxonomically and described based on a single specimen collected from Jeju Island, Korea. “Min-be-do-ra-chi” was identified as Z. major by the following morphological characteristics: U-shaped markings on the dorsal and anal fins, 31 dorsal fin spines, 78 dorsal fin soft rays, 87 anal fin soft rays, and 109 vertebrae. In contrast, Z. glaber has triangular markings on the dorsal and anal fins, 92–96 anal fin soft rays, and 112–122 vertebrae. Therefore, our results suggest that the scientific name of this species reported previously as Z. glaber should be changed to Z. major.

More than one way to be an herbivore: convergent evolution of herbivory using different digestive strategies in prickleback fishes (Stichaeidae)

In fishes, the evolution of herbivory has occured within a spectrum of digestive strategies, with two extremes on opposite ends: (i) a rate-maximization strategy characterized by high intake, rapid throughput of food through the gut, and little reliance on microbial digestion or (ii) a yield-maximization strategy characterized by measured intake, slower transit of food through the gut, and more of a reliance on microbial digestion in the hindgut. One of these strategies tends to be favored within a given clade of fishes. Here, we tested the hypothesis that rate or yield digestive strategies can arise in convergently evolved herbivores within a given lineage. In the family Stichaeidae, convergent evolution of herbivory occured in Cebidichthys violaceus and Xiphister mucosus, and despite nearly identical diets, these two species have different digestive physiologies. We found that C. violaceus has more digesta in its distal intestine than other gut regions, has comparatively high concentrations (>11mM) of short-chain fatty acids (SCFA, the endpoints of microbial fermentation) in its distal intestine, and a spike in β-glucosidase activity in this gut region, findings that, when coupled to long retention times (>20h) of food in the guts of C. violaceus, suggest a yield-maximizing strategy in this species. X. mucosus showed none of these features and was more similar to its sister taxon, the omnivorous Xiphister atropurpureus, in terms of digestive enzyme activities, gut content partitioning, and concentrations of SCFA in their distal intestines. We also contrasted these herbivores and omnivores with other sympatric stichaeid fishes, Phytichthys chirus (omnivore) and Anoplarchus purpurescens (carnivore), each of which had digestive physiologies consistent with the consumption of animal material. This study shows that rate- and yield-maximizing strategies can evolve in closely related fishes and suggests that resource partitioning can play out on the level of digestive physiology in sympatric, closely related herbivores.

First Record of Ernogrammus zhirmunskii (Actinopterygii: Cottiformes: Stichaeidae) from Japan, with a Description and a Revised Diagnosis

Sixteen specimens of Ernogrammus zhirmunskii Markevich and Kharin, 2011, formerly known only from Peter the Great Bay, Russia, were collected from Volcano Bay on the Pacific coast of Hokkaido and from Shizugawa Bay, Miyagi Prefecture, Pacific coast of the northern Honshu, Japan. This species is redescribed on the basis of these specimens and several errors in the original description are corrected. This species is easily distinguished from other stichaeid fishes in having a diagnostic lateral-line pattern and a rigid spine in the posteriormost part of the anal fin.

New records of a stichaeid fish, Alectrias cirratus, from Japan

New records of a stichaeid fish, Alectrias cirratus, from Japan

A new species of prickleback Ernogrammus zhirmunskii (Acanthopterygii: Perciformes: Stichaeidae) from the Sea of Japan, Russia

A new stichaeid fish, Ernogrammus zhirmunskii is described on the basis of the specimens collected in Peter the Great Bay, the Sea of Japan. This new species differs from its congeners E. hexagrammus and E. walkeri in having seven body sensory canals in total number including one short canal in the middle of belly and unique combination in number of the anal fin rays with one short rigid spine posteriormost (I 28-30 I). In coloration the fish has one narrow white stripe between two wide black ones on the base of pelvic fin, and one dark blotch on the dorsal fin anteriorly.

A new genus and species of prickleback (Perciformes: Stichaeidae) from Japan

A stichaeid fish, Xenolumpenus longipterus gen. et sp. nov., is described on the basis of 2 specimens (107.1–114.9 mm in standard length) collected from 167 to 300 m in the northern Sea of Japan off southern Hokkaido, Japan. Xenolumpenus is unique among all known genera of the subfamily Lumpeninae in having all pectoral, pelvic, and anal fin rays elongate and unbranched with fin membranes well-incised. Xenolumpenus longipterus can be further distinguished from all species of the subfamily in having the following combination of characters: dorsal fin XLVI–XLVIII; anal fin II, 28–29; pectoral fin 11; large black blotches on pectoral fin; and black ocellus on caudal fin.

A comparison of absorption and assimilation efficiencies between four species of shallow- and deep-living fishes

We captured two species of deep-sea zoarcids, Melanostigma pammelas and Lycodapus mandibularis, from Monterey Bay California and maintained them in the laboratory. One shallow-water zoarcid, Eucryphycus californicus, and an ecologically and morphologically similar stichaeid fish Xiphister atropurpureus were collected from intertidal and subtidal habitats in Monterey Bay. We investigated the absorption and assimilation efficiencies of these fishes to determine whether deep-sea species have evolved mechanisms to increase their efficiency of food use. Fishes were placed in experimental chambers and fed a known quantity of food. Ammonia excretion was measured and feces were collected daily. Both food and feces were analyzed for water, protein, lipid and ash to determine specific absorption efficiencies. Absorption ranged from 87.7 to 92.4% and assimilation efficiencies from 84.0 to 86.5%. Meal sizes from 0.5 to 4.0% of body weight did not affect the results. No significant differences were found between deep-sea and shallow-water species fed single meals or fed ad libitum for 10 days. This suggests that the selective pressure to maximize absorption and assimilation is universal and is not affected by the productivity of the habitat occupied. However, the relative size of the intestine in the deep-sea species was significantly smaller suggesting that they had a lower metabolic cost to maintain their digestive apparatus. It could not be concluded whether this was the result of pressure to conserve energy or rather the tendency of the shallow-living species to ingest more refractory material (i.e. sediment, algae).

Lumpenopsis clitella: A New Species of Prickleback (Teleostei: Stichaeidae) from Southern California, with Comments on Lumpenopsis Soldatov

Abstract A new species of stichaeid fish referable to the genus Lumpenopsis Soldatov is described based on two specimens from Southern California. The Saddled Prickleback, Lumpenopsis clitella n. sp., is remarkably similar in body form and coloration to the type species of the genus, Lumpenopsis pavlenkoi Soldatov, 1916, known from the northwestern Pacific. The two species differ in number of anal-fin spines (one in L. clitella vs two in L. pavlenkoi), cheek squamation (absent vs present), and in modest details of meristics and coloration. Among North American pricklebacks, the Saddled Prickleback is most similar to the Y-Prickleback, Allolumpenus hypochromus Hubbs and Schultz, 1932. The holotype and only specimen on which the descriptions of that genus and species were based, reportedly lacked vomerine and palatine teeth, a character used to distinguish Allolumpenus from Lumpenopsis. The holotype of A. hypochromus cannot be located, but examination of two more recently collected specimens indicates the p...

Biplexiform ganglion cells in the retina of the perciform fish Pholidapus dybowskii revealed by HRP labeling from the optic nerve and optic tectum

Using retrograde HRP labeling from the optic nerve (ON) or optic tectum (OT), we have visualized biplexiform cells in wholemounted retinas of the stichaeid fish Pholidapus dybowskii and studied their morphology and spatial properties. Biplexiform cells labeled from the ON were similar in their morphology to biplexiform cells found in other fishes. Their distribution across the retina was non-random and independent of that of other large ganglion cell types. Biplexiform cells labeled from the OT, too, formed non-random mosaics, whose spatial properties suggested that most or all biplexiform cells project to the OT in this species. We propose that biplexiform cells in Pholidapus are homologous to biplexiform cells in other fishes (lower vertebrates). Pholidapus biplexiform cells may participate in the tectum-mediated visual reactions.

Zoarchias microstomus, a New Stichaeid Fish from Northeastern China

A new stichaeid fish, Zoarchias microstomus, is described on the basis of 7 specimens (80.3-103.1 mm TL) collected from Dalian, Liaoning Province, northeastern China. This species is similar to Z. uchidai from Korean waters in general appearance and meristic counts, but differs from it in having a smaller head and mouth, and truncated gill raker tips.

Growth, consumption, assimilation and excretion in the marine herbivorous fish Cebidichthys violaceus (Girard) fed natural and high protein diets

Laboratory feeding trials were conducted to determine the growth and food processing rates and gut retention times of a wild, cool-temperate zone fish fed its simulated summer diet of seaweeds and two higher protein diets more typical of those of carnivorous fishes. When this stichaeid fish, Cebidichthys violaceus (Girard), was fed for 12 wk on a pelleted natural summer diet (10% protein) and on this food modified to make two higher (30 and 50%) protein diets, the fish grew equally fast on the 10 and 50% protein diets but most rapidly on the 30% protein regimen. Rates of food consumption and assimilation and energy consumption were lower for fish on the highest protein diet than for those on the other two diets. The energy assimilation rate was lower for fish on the 10% protein diet than for those on the 30% diet, but neither rate was different from that for fish on the 50% protein diet. Gut retention times were shorter for fish on the lowest protein diet, yet nitrogen consumption, assimilation and excretion rates were not different for fish on the three diets, suggesting that C. violaceus feeds to meet a nitrogen (protein) requirement. That the nitrogen excretion rate did not increase with an increase in dietary protein content may be explained at least in part by the marked decrease in food consumption rates with increase in dietary protein levels.

Effects of diets of different protein content on food consumption, gut retention, protein conversion, and growth of Cebidichthys violaceus (Girard), an herbivorous fish of temperate zone marine waters

Laboratory feeding trials provided the first evidence that a temperate zone fish can grow on a seaweed diet. When the stichaeid fish Cebidichthys violaceus (Girard) was fed for 12 wk on a pelleted seaweed-only diet representing its natural summer diet (10% protein) and on the food modified to make lower (7%) and higher (19%) protein diets, the fish grew on all three but more rapidly on the two higher protein regimens. Maintenance requirements for food and protein of C. violaceus were strikingly low compared to values reported for other fishes. Gut retention times were significantly shorter for fish on the lower protein diet, yet fish consumed equal amounts of energy on the three diets, suggesting that C. violaceus feeds to meet an energy requirement. Nevertheless, the fish converted food protein to body protein with the same efficiency on all three diets and with equal or greater efficiency than those that have been reported for carnivorous fishes.

Effects of macrophyte secondary chemicals on food choice and digestive efficiency of Cebidichthys violaceus (Girard), an herbivorous fish of temperate marine waters

Laboratory experiments using prepared seaweed food strips coated with the extracts of two dietary and four nondietary macrophytes provided evidence that the feeding of cold-water hervivorous fish is deterred chemically by at least one brown algal species. Neither polar nor nonpolar extracts of the dietary algae Iridaea splendens (Turn.) Bory and Ulva lobata (Kütz) S. et G. or the nondietary macrophytes Laurencia spectabilis Post. & Rupr., Macrocystis integrifolia Bory and Phyllospadix scouleri Hook applied to the food strips reduced feeding by the stichaeid fish Cebidichthys violaceus (Girard). Only food strips coated with a polar extract of the nondietary fucoid brown alga Fucus gardneri Silv. significantly reduced feeding by C. violaceus. Moreover, the polar extract of F. gardneri but not that of the laminarian brown alga M. integrifolia coated on the dietary alga Ulva lobata reduced the digestibility of this alga when force-fed to C. violaceus. Specifically, the assimilation of N by C. violaceus was significantly reduced. These results partially explain food choice in this herbivorous fish and help explain why fucoid algae are not eaten by north temperate herbivorous fishes.

Esselenia, a New Genus of Pricklebacks (Teleostei: Stichaeidae), with Two New Species from California and Baja California Norte

Esselenia, a new genus of the family Stichaeidae, contains relatively small, elongate, benthic fishes that resemble Cebidichthys in having the dorsal fin softrayed posteriorly, but differ in meristics of the vertical fins and axial skeleton, and in having two or three lateral lines. The two known species inhabit shallow waters from central California to northern Baja California. Esselenia carli is described from 49 specimens collected from Monterey Bay, California, to near the mouth of Rio Santo Tomas, Baja California Norte, to a depth of 26 m. It is distinguished by its lack of pelvic fins, first dorsal spine associated with the second pterygiophore, first anal pterygiophore not enlarged, 19-23 soft dorsalfin rays, 65-70 vertebrae, and ventrolateral lateral lines connected across the breast in an arc that is bisected by a medioventral lateral line that extends from the isthmus to fork about the anus. Esselenia laurae is described from 15 specimens collected near Southeast Farallon Island, California, to Punta Banda, Baja California Norte, to a depth of 46 m. It is distinguished by its minute pelvic fins, first dorsal spine associated with the first pterygiophore, enlarged first anal pterygiophore, 14-18 soft dorsal-fin rays, 60-62 vertebrae, ventrolateral lateral lines not connected across the breast, and no medioventral lateral line. A stichaeid fish collected off the mouth of Rio

Neolumpenus unocellatus, a new genus and species of stichaeid fish from Japan

Neolumpenus unocellatus gen. et sp. nov., a stichaeid fish (subfamily Lumpeninae,sensu Makushok, 1958) is described on the basis of a single specimen found in the stomach of the Pacific cod,Gadus macrocephalus Tilesius, caught off Akkeshi, Hokkaido, Japan. The new genus and species is distinguished from all other lumpenines in having the following combination of characters: 1) 51 dorsal spines, 33 anal fin rays, 57 total vertebrae; 2) broad pelvic fin with deeply-branched soft rays; 3) lower rays of pectoral fin branched and not prolonged backward; 4) prevomerine and palatine teeth present; 5) pungent spines present in pelvic and anal fins; 6) upper lip fused to snout anteriorly; 7) gill openings not extending forward beyond a vertical through posterior margin of eye; 8) minimal (fifth) hypural present; 9) first interneural spine inserted between first and second neural spines; 10) extremely large cephalic sensory pores present; 11) high, steep snout; 12) ocellus on dorsal base of caudal fin.

New and rare stichaeid fishes from the Okhotsk Sea

Two stichaeid fishes were collected off the Okhotsk coast of Hokkaido in Japan. One represents a new species,Stichaeus fuscus, which differs from all other species of this genus in meristics, color pattern, shape of the pelvic fin, and body proportions. The other species is identified asSoldatovia polyactocephala (Pallas) and is redescribed.

Herbivore responses to a seasonally fluctuating food supply: Growth potential of two temperate intertidal fishes based on the protein and energy assimilated from their macroalgal diets

The protein and energy assimilated from eight main dietary algae by the stichaeid fishes Cebidichthys violaceus (Girard) and Xiphister mucosus (Girard) were calculated using bimonthly data on the chemical compositions (carbohydrate, protein, lipid) of these algae and the stomach contents and assimilation efficiencies of the two fish species. The effects of food choice on diet quality were estimated by comparing the amounts of energy and protein determined to be assimilated from the actual (selective) diets with those that would be assimilated from hypothetical (nonselective) diets based on algal availability. Both fishes consumed carbohydrate-rich, protein-poor algae in the winter and protein-rich, carbohydrate-poor algae during the rest of the year. Thus, contrary to an expectation from optimal diet theory, energy intake was increased by selection only during winter, whereas protein intake was increased at the expense of energy intake at all other times. Growth rates of the two fishes predicted by a growth curve based on the relative amounts of protein and energy assimilated from their diets were at or just above maintenance levels in winter and higher during other times of the year. The additional species of algae and the small amounts of animal material in the diets of the two fishes appeared not to alter substantially the predicted annual growth pattern. Although Cebidichthys violaceus and Xiphister mucosus seem to be able to grow during most times of the year on a completely algal diet, their rates of energy consumption, which in turn regulate protein intake, are unknown and must be examined before more definite conclusions can be drawn about the growth of these fishes.

New and Rare Stichaeid Fishes from the Okhotsk Sea

New and Rare Stichaeid Fishes from the Okhotsk Sea

A new stichaeid fish of the genusAlectrias from Mutsu Bay, northern Japan

Alectrias mutsuensis sp. nov. is described on specimens collected from Mutsu Bay, Aomori Pref. This new species is rather deep dweller compared to other species of the genus, living on muddy bottoms, about 20 to 40 meters deep, and is diagnosed by the following characters: dermal crest on head reaching to occipital region; distance between end of dermal crest and dorsal fin origin less than eye diameter; end of anal fin separated from caudal fin; anterior dorsal spines before anal origin, slender and flexible; epaxial hypurals mostly fused into a single plate. A key to all nine species belonging to the subfamily Alectriinae is presented.

New genus and species of the family stichaeidae from Hokkaido, Japan

Specimens of a new genus and species of the stichaeid fish,Leptostichaeus pumilus, were collected from the Okhotsk Sea off Hokkaido in Japan. The present new genus and species clearly differs from all the other genera and species of the stichaeid fishes in the following characters: 3 or 4 pectoral fin rays; 10 or fewer caudal principal rays; 79–82 dorsal spines; no pelvic fin; last interneural spine supporting a single dorsal spine; infraorbital, occipital and lateral line canals absent; moderate size of dorsal spine shorter than eye diameter; membranes of dorsal and anal fins widely connected with caudal fin; a large black spot divided by a yellow band present just above gill cover.