Phyllospadix schouleri, and algae such as Laminaria, Iridia, Porphyra, and Corallina (Nakamura 1976a). However, because the fluffy sculpin does not inhabit high tide pools that have this macrophytic cover, it is believed that latitudinal placement (and/or temperature) plays a more significant role than vegetation in habitat choice (Nakamura 1976a). Based upon experimental evidence (Nakamura 1976a), it is believed that the most highly preferred habitat of is low to mid-intertidal pools with eelgrass and a sand substrate. Its second preference was shown to be a rock-sand zone, and its least preferred habitat is the open, sand-only zone. Fluffy sculpins are capable of aerial breathing for extended periods (hours) of time, during which their respiration rate seems to remain stable (Yoshiyama 1994). It is thought that this stable air breathing may be a response to the preference of for vegetated cover, which may expose it to frequent reductions in low-oxygen waters at night, due to respiration by the covering plants (Yoshiyama 1994). (Freeman, et al., 1985; Grossman and de Vlaming, 1984; Nakamura, 1976a; Nakamura, 1976b; Yoshiyama and Cech, 1994)is most commonly found in temperate, rocky, subtidal and low intertidal pools, though it is also found frequently in mid-intertidal pools. Due to its numerical domination in “the rocky fish assemblage”, it is suggested that , “plays an important role in the functional organization of the intertidal community” (Grossman 1984). is rarely found in high intertidal pools, and it is believed that it almost universally prefers the stability and cooler temperatures of the low intertidal pools (Freeman 1985, Nakamura 1976b). Experiments have shown that strongly prefers low tidal pools with vegetation such as eelgrass,
Fluffy sculpins are believed to be stenothermal (Moring 1981), and it is suggested that this requirement for a stable temperature range restricts this species to low intertidal pools, and explains the dominance of this species in tidal pools from Central California to British Columbia, where the temperature range is less extreme than in areas further to the north or south. Laboratory tests have demonstrated that Oligocottus maculosus, which resides is the high intertidal zone (Nakamura 1976b). This evidence supports the observed preference of for the lower, more stable pools and may support hypotheses that is more successful in northerly climates. Interestingly, Zamzow found that fish, including , in low intertidal pools have fewer ultraviolet processing compounds than species that occupy the high intertidal zone. The reduction in these compounds may be associated with the preference of for more vegetative cover and lower tidal pools (Zamzow 2003). (Moring, 1981; Nakamura, 1976b; Zamzow, 2003; Moring, 1981; Nakamura, 1976b; Zamzow, 2003)has less tolerance for long-term increases in heat exposure than does its close relative
- Other Habitat Features
- intertidal or littoral
- Average elevation
- 0 m
- 0.00 ft
- Average depth
- 0 m
- 0.00 ft
Oligocottus maculosus, the tidepool sculpin, which is abundant in the high intertidal zone of the east Pacific shore. However, O. maculosus is distinguishable by its larger size (Yoshiyama, 1980), its habitation of the high intertidal zone, by its color and pigmentation, and by the number and rows of cirri on the lateral body surface (Nakamura 1976b). Though these two species share similar morphology and their habitats slightly overlap vertically, they do not appear to compete for energy or space resources, due to a distinct partitioning of resources. However, this resource partitioning does suggest that competition for resources between these two species drove their evolution in the past, which may have resulted in their current “niche complementarity” (Yoshiyama, 1980). (Nakamura, 1976b; Yoshiyama, 1980)is close morphologically to
- Sexual Dimorphism
- male larger
- Average mass
- 8.0 g
- 0.28 oz
- Range length
- 13 to 101 mm
- 0.51 to 3.98 in
- Average length
- 89 mm
- 3.50 in
It has been stated that the life histories of intertidal fishes, and especially cottids, are not well-understood (Freeman, 1985). In general, it is suggested that fluffy sculpins mature early and are short-lived (Freeman, 1985). It is also thought that the life history and development of (Freeman, et al., 1985)is intricately connected to its fluctuating tidal environment. It has been demonstrated that the growth of is influenced by seasonal fluctuations in nutrients caused by upwellings along the East Pacific Coast (Freeman, 1985). Instantaneous growth rates in fluffy sculpins were shown to be highest during the nutrient rich upwellings (April to August) and lowest during the low productivity Ocean-Davidson current period (October to February) (Freeman, 1985).
Fluffy sculpins develop through larval, post larval, juvenile and adult stages. Eggs are fertilized internally (Morris, 1956), are deposited on rocks, and are guarded by the males (Oregon State University, 2003b). Further details regarding egg deposition and hatching were not found in the literature. The diagnostic characteristics of the larval stage in O. maculosus larvae by a “bubble of skin interior to the origin of the dorsal finfold that is unpigmented and less obvious” (FishBase, 2004). Additionally, the larval head and nape are lightly pigmented (FishBase, 2004). It is believed that larval metamorphosis is timed to coincide with the nutrient rich upwellings that occur along the East Pacific Coast from April to August (Freeman, 1985). There is little information on the post-larval stages of and it is not known how post-larvae “settle” in particular pools, but the data suggests that temperature plays a factor in the choice of pools, and that an internal threshold temperature is determined in the larval or post-larval stage (Nakamura 1976b). It is believed that juveniles mature and are capable of spawning within their first year (Freeman, 1985), and the data suggests that males exceed females in growth during their second year (Freeman, 1985; Morris 1956). (FishBase, 2004; Freeman, et al., 1985; Morris, 1956; Nakamura, 1976b; Oregon State University, 2003)are a “patch of parietal spines; 10 to 12 spines that develop along preopercular margin; and 8 to 10 accessory spines that form anteriorly at the bases of the preopercular spines” (FishBase, 2004). larvae are distinguished from
- Development - Life Cycle
According to Grossman, there is no substantial reproductive data on intertidal fishes or cottids (Grossman, 1984). Morris (1956), in studying the anatomy of the male (Grossman and de Vlaming, 1984; Morris, 1956; Oregon State University, 2003)clasping anal spine did observe mating in a laboratory setting. He stated that, “no definite patterns of display or courtship were apparent and copulation took place in an atmosphere of carefree promiscuity” (Morris, 1956). Of course, this behavior could be solely attributed to the artificial setting. reproduces using internal fertilization, and the males have a developed penis and clasping anal ray that assist in this process (Morris, 1956). The first anal ray on the males is set apart and is prehensile. The male “bends this ray anterolaterally around the female” and uses it to hold the two fish together as they mate. This ray can bend to the right or left and thus male fluffy sculpins are able to approach females from either side. It is suggested that clasper flexing is stimulated by visual or touch stimuli (Morris, 1956). Morris witnessed mating taking place away from the substrate and lasting 4 to 5 seconds, again in a laboratory setting. Internally fertilized eggs are laid on rocks and are guarded by the males (Oregon State University, 2003b).
It is hypothesized that most fluffy sculpins are large enough to spawn within their first year, but it is not clear how many survive to do so (Freeman, 1985). The literature suggests that the reproductive cycle in (Freeman, et al., 1985)females is strongly coordinated with the nutrient upwelling and downwelling cycles that occur along the East Pacific Coast (Freeman, 1985). Freeman found that ovarian recrudescence occurs in females during the downwelling period (October to February) during which time the water is not as nutrient rich and instantaneous growth rates are slow, but during which time females are observed to eat more than males. It is assumed that this excess energy is used in egg production (Freeman, 1985). In Freeman’s study at Dillon Beach, CA, strong seasonal fluctuations in the feeding and reproduction of fluffy sculpins were observed. Due to the fact that females contain vitellogenic oocytes from October through May, Freeman hypothesizes that females spawn more than once per year and do so during the winter and spring. Following this hypothesis, larval metamorphosis, and possibly recruitment, could be timed to occur with the seasonal nutrient upwellings (Freeman, 1985). It is also hypothesized that reproductive success rates may improve as males age because of their increased body and clasper size (Freeman, 1985).
A detailed study of the follicular development in female fluffy sculpins has been conducted by Grossman (1984), who found that follicular development is consistent with that of other oviparous teleosts. Two to four clutches were observed in females between October and May, and Grossman hypothesizes that the female breeding period may last from six months (November to April) to eight months (October to May); rapid follicular enlargement was seen in September. The fact that clutches found in females during this time were in differing stages of development is evidence of asynchronous reproduction and the multiple spawning events also described by Freeman. (Freeman, et al., 1985; Grossman and de Vlaming, 1984)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- In the late autumn and early spring of temperate North America
- Breeding season
- From November to April, or possibly from October to May
- Average age at sexual or reproductive maturity (female)
- 1 years
- Average age at sexual or reproductive maturity (male)
- 1 years
- Parental Investment
The lifespan and longevity ofappears to be strongly affected by its environment. While one study in the wild found only two age classes of fluffy sculpin present, 0+ and 1+ (Freeman, 1985), another study found individuals of 2+ years (Moring, 1981). In captivity, has survived for more than two years (Yoshiyama 1992). Because they have no scales, they are more difficult to age (must use a vertebral aging method), and relatively little is known of their early life history (Nakamura, 1976b).
Freeman hypothesized that the shorter lifespan (1.5 years) and the small size of the fluffy sculpins he studied might be the result of the strong seasonal fluctuations at his field site. He suggests that the further north the species is located (within its ideal range from Central California to British Columbia) the longer its lifespan will be due to reduced temperature fluctuation. There is also reduced exposure to ultraviolet radiation further north, which could contribute to the increased lifespan of more northerly populations, though there is not concrete evidence for this (Zamzow, 2003). (Freeman, et al., 1985; Moring, 1981; Nakamura, 1976b; Yoshiyama, et al., 1992; Zamzow, 2003)
- Range lifespan
- 1 to 2 years
- Range lifespan
- Average lifespan
- 2 years
- Average lifespan
- Range lifespan
- >2 (high) years
- Range lifespan
- Average lifespan
- >2 years
- Average lifespan
As in many other intertidal fishes, a homing mechanism has been documented in (Freeman, et al., 1985; Grossman and de Vlaming, 1984; Moring, 1981; Nakamura, 1976a; Nakamura, 1976b; Yoshiyama, et al., 1992), and it is suggested that fluffy sculpins occupy home ranges of more than one pool (Yoshiyama, 1992). It is suggested that the fluctuating intertidal environment demands that fishes, such as be able to find and recognize safe spots (Yoshiyama, 1992). Fluffy sculpins have been observed to return to their home pools even if it is necessary to cross exposed, ‘inhospitable’ habitat to do so (Yoshiyama, 1992). They have also returned to home pools even if transplanted into other equally suitable habitats (Yoshiyama, 1992). However, for it seems that “site fidelity and homing success depend upon local topographic characteristics and other environmental factors (e.g. exposure to wave action, frequency of habitat perturbations)” (Yoshiyama, 1992). For example, evidence suggests that may lose the drive to return home if unsuccessful for a certain period of time (Yoshiyama, 1992). Also, it is not clear whether fluffy sculpins simply “wander” back home, or if they rely upon distinct visual or olfactory cues (Yoshiyama, 1992). In general, larger individuals seem to be more successful at homing than are smaller individuals. It is not clear how young may use homing to move through the intertidal zone, though the absence of dead young in unsuitable habitats (such as the high intertidal pools) suggests that pools are non-randomly selected, and that site fidelity is established in the post-larval stage, possibly by temperature cues (Yoshiyama, 1992). Temperature does seem to be an overarching factor in habitat selection by (Freeman, 1985; Moring, 1981; Grossman, 1984; Nakamura, 1976a, b; Yoshiyama, 1992).
In regards to interspecies relationships, Oligocottus maculosus. The spatial habitat of the two species overlaps slightly in the mid-intertidal range. However, they eat different food and prefer different habitats. When occupying a tank together, they show no signs of aggression (Nakamura, 1976a). (Nakamura, 1976a)displays no competitive or aggressive behavior in the presence of the closely related tidepool sculpin,
Perhaps most interesting behaviorally is the ability of O. maculosus can breathe for extended periods of time out of water (hours). is a particularly interesting air breather because its respiratory rates in air and in water are similar and stable, whereas the closely related O. maculosus has a greatly increased respiration rate out of water (Yoshiyama and Cech, 1994). This seems counterintuitive, as occupies the more stable subtidal and low intertidal zones, which do not fluctuate in water level or temperature as greatly as do the high intertidal zones in which O. maculosus lives. However, the strong affinity that has for vegetative cover indicates that it may inhabitat pools that experience low oxygen levels at night, when photosynthetic rates are low (Yoshiyama and Cech, 1994). Low oxygen levels, in turn, may demand an increase in air breathing. No information in the literature was found detailing the nocturnal behavior of . (Yoshiyama and Cech, 1994)to breathe aerially. The literature states that only a few marine fish families (Stichaeida, Pholididae, and Cottidae) are air breathing (Yoshiyama and Cech, 1994). However, several temperate zone rocky intertidal fish are able to breathe aerially (Yoshiyama and Cech, 1994), presumably due to their need to adapt to the constant change in tidally influenced environments. Both and
The home range of (Yoshiyama and Cech, 1994)is hypothesized to encompass multiple intertidal pools (Yoshiyama and Cech, 1994).
Communication and Perception
The literature suggests that fluffy sculpins do communicate with mates, as is evident by males’ use of their claspers during intercourse (Morris, 1956). The extent to which communication occurs during mating is unclear, but males use their claspers to hold onto females during the internal fertilization process. While the literature does not suggest how mates find each other, it is assumed that they use visual perception channels to some extent.
Communication and perception betweenand its physical surroundings is evident in the homing ability of the species. It appears that uses pool temperature to determine whether it is in its appropriate pool range (Nakamura, 1976). However, it would seem that must utilize homing indicators in addition to temperature, as the species is able to distinguish between its home pool and other pools that are similar in temperature and overall habitat quality (Yoshiyama, 1992). It is suggested in the literature that visual and olfactory perception may assist the fluffy sculpins in homing (Yoshiyama, 1992). Furthermore, larger individuals were significantly better at homing than were smaller individuals (Yoshiyama, 1992), implying that visual and olfactory sensory abilities may increase with body mass. It is interesting to note that has been observed to lose its homing drive after repeated failed homing attempts (Yoshiyama, 1992), indicating that sensory systems, whether olfactory or visual, may adjust to stimuli from new pools given time.
In a laboratory setting, O. maculosus was more covert in its hunting (Yoshiyama, 1980). Yoshiyama hypothesizes that this results in consuming fewer shrimp than does O. maculosus (Yoshiyama, 1980). In turn, he suggests that the development of these slightly different predatory strategies and dietary compositions contributes to the ability of these two species to live in such close proximity to one another without intense competition. (Yoshiyama, 1980)captured prey by charging it directly, whereas
- Primary Diet
- eats non-insect arthropods
- Animal Foods
- aquatic or marine worms
- aquatic crustaceans
- other marine invertebrates
While anecdotal evidence of predation of (University of Washington Fish Collection, 1996)by birds and larger fish was found, no documentation of specific predators was found in the literature.
While the numerical dominance ofin subitdal and low to mid-intertidal pools indicates that it plays a signifant role in the funtioning of these highly fluctuating and specialized ecosystems, no studies investigating the specific role of fluffy sculpins in these ecosystems were found in the literature.
Economic Importance for Humans: Positive
It has been suggested thatmay be a suitable and/or desirable ornamental fish (Oregon State University, 2003a), but no detailed evidence has been found in the literature.
is intrinsically beneficial to humans because it contributes to the biodiversity and ecosystem functioning of the intertidal zone, which in turn supports the highly productive neritic zone of the Pacific Coast of North America. This is a highly productive ecological region that supports critical fisheries and the larger oceanic ecosystem as a whole.
Economic Importance for Humans: Negative
There are no known adverse effects ofon humans.
is not listed on any of the conservation status sites.
- IUCN Red List [Link]
- Not Evaluated
Greeley was first described in 1898, in Jordan and Evermann’s, The Fishes of North and Middle America: a descriptive catalogue of the species of fish-like vertebrates found in the waters of North America north of the Isthmus of Panama (FishBase, 2004).
The author noted that multiple unpublished doctoral dissertations were referenced in the literature. These sources were unaccessible to the author, but they may provide additional and/or more current information on the life history and behavior of (FishBase, 2004).
George Hammond (editor), Animal Diversity Web.
Lauren Theodore (author), University of Michigan-Ann Arbor, William Fink (editor, instructor), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- Pacific Ocean
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.
- bilateral symmetry
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
the nearshore aquatic habitats near a coast, or shoreline.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
- internal fertilization
fertilization takes place within the female's body
- intertidal or littoral
the area of shoreline influenced mainly by the tides, between the highest and lowest reaches of the tide. An aquatic habitat.
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
specialized for swimming
- native range
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- saltwater or marine
mainly lives in oceans, seas, or other bodies of salt water.
- seasonal breeding
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- sexual ornamentation
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
uses sight to communicate
FishBase, 2004. "Oligocottus snyderi (species summary)" (On-line). Accessed October 22, 2004 at http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=4131&genusname=Oligocottus&speciesname=snyderi.
Freeman, M., N. Neally, G. Grossman. 1985. Aspects of the life history of the fluffy sculpin, Fishery Bulletin, 83 (4): 645-656..
Grossman, G., V. de Vlaming. 1984. Reproductive ecology of an intertidal sculpin, Oligocottus snyderi. Journal of Fish Biology, 25: 231-240.
Moring, J. 1981. Seasonal Changes in a Population of the Fluffy Sculpin Oligocottus snyderi from Trinidad Bay, California, USA. California Fish and Game, 67(4): 250-253.
Morris, R. 1956. Clasping mechanism of the cottid fish, Oligocottus snyderi Greeley. Pacific Science, 10: 314-317.
Nakamura, R. 1976. Experimental Assessment of Factors Influencing Micro Habitat Selection by Two Tide Pool Fishes, Oligocottus maculosus and Oligocottus snyderi. Marine Biology, 37(1): 97-104.
Nakamura, R. 1976. Temperature and the Vertical Distribution of Two Tide Pool Fishes, Oligocottus maculosus and Oligocottus snyderi. Copeia, (1): 143-152.
Oregon State University, 2003. "Fluffy Sculpin" (On-line). Accessed October 22, 2004 at http://hmsc.oregonstate.edu/projects/msap/PS/masterlist/fish/fluffysculpin.html.
Oregon State University, 2003. "Potential Ornamental Aquaculture Species" (On-line). Accessed October 22, 2004 at http://hmsc.oregonstate.edu/projects/msap/PS/topornamentals.html.
Oregon State University, 1998. "The Tide Pool Page : Sculpins" (On-line). Accessed October 22, 2004 at http://hmsc.oregonstate.edu/projects/rocky/sculpin.html.
University of Washington Fish Collection, 1996. "Family Cottidae, Sculpins" (On-line). Accessed October 22, 2004 at http://artedi.fish.washington.edu/FishKey/cott.html.
Yoshiyama, R. 1980. Food habits of three species of rocky intertidal sculpins. Copeia, (3): 515-525.
Yoshiyama, R., J. Cech. 1994. Aerial respiration by rocky intertidal fishes of California and Oregon. Copeia, (1): 153-158.
Yoshiyama, R., M. Philippart, T. Moore, J. Jordan, C. Coon, L. Schalk, C. Valpey, I. Tosques. 1992. Homing behavior and site fidelity in intertidal sculpins. Journal of Experimental Marine Biology and Ecology, 160: 115-130.
Zamzow, J. 2003. Ultraviolet-absorbing compounds in the mucus of temperate Pacific tidepool sculpins: variation over local and geographic scales. Marine Ecology Progress Series, 263: 169-175.