Preface. About This Book. Area and Species Covered. Names and Sequence of Species

Transcription

1 Preface About This Book We developed this book to fulfill the need for a comprehensive, current, and compact field guide to fishes of the Pacific northwest and as a companion to A Field Guide to Coastal Fishes: From Maine to Texas. We hope that this book is as well received as Maine to Texas, and does even more good work. Area and Species Covered The species included are brackish and marine fishes that are encountered from the northern border of Alaska to the southern border of California. This area generally extends from the intertidal zone to depths of about 660 feet (200 meters). We provide identification and natural history information for most fishes we know to have stable populations within this range of coverage. This includes all native and several non-native fishes that spend all or part of their adult lives in marine waters. We also describe species that are predominantly freshwater inhabitants but are also found in low-salinity waters. For comprehensiveness, some deep-water species and their families are included. Rare species and those generally occurring below 660 feet have been mostly omitted. Other poorly documented species were excluded for lack of information such as specimen photographs or video clips for live color reference. Many of the fishes that occur from Alaska to California also occur at other, often distant, locations. Strays and waifs may be found in areas outside of the species typical range. Wherever possible, those locations are noted in the text. Most of the fishes found in the southern waters of the western United States also occur off of Baja California and adjacent waters; thus the range map includes this broader area. Names and Sequence of Species The Latin and common names of the families in this book follow those presented in Fishes of the World, fourth edition, by Joseph S. Nelson. The common names of species are taken from Common and Scientific Names of Fishes from the United States, Canada, and Mexico, seventh edition, published by the American Fisheries Society (AFS), Special Publication 34. With a few exceptions, Latin names, authority, and date follow Eschmeyer s most recent online Catalog of Fishes. The orders and families of fishes are organized in phylogenetic sequence following Fishes of the World. The inclusion of Scaridae in Labridae and splitting of Serranidae and Epinephelidae follow the most recent research. Sequences of species within each family follow the alphabetical order of genus and species names, rather than the alphabetical order of common names, with Pipefishes being the only exception. For example, the following Rockfishes are listed as: 14 Rougheye Rockfish - Sebastes aleutianus Pacific Ocean Perch - Sebastes alutus Kelp Rockfish - Sebastes atrovirens

2 Preface The first letter of each word in single- and multiple-word names is capitalized, except after a hyphen, unless that word requires capitalization as a proper noun. This is in accordance with recent changes adopted by the American Fisheries Society and as published in Common and Scientific Names of Fishes from the United States, Canada, and Mexico, seventh edition, Special Publication 34, AFS. Although we elected to use the most recently accepted AFS common names for the individual species, other commonly used local names or those accepted by the Food and Agriculture Organization are also mentioned wherever possible. Whenever we encountered errors or conflicting information in regard to Latin or common names, we made appropriate corrections and inclusions based on the most recently published documentation. Organization and Presentation We have arranged this book into three primary sections: Introduction, Families, and Species. These sections are supported by supplemental materials, which include a glossary of terms, a list of additional resources, descriptions of rare species also in the area, and an index. The Introduction provides an overview of the evolution, diversity, and features of fishes. It also includes information that will help the user identify fishes. Each family section describes, in concise terms, each of the 157 families of fishes that are found along the coast from Alaska to California. A printable Key to Families presented in this book is available online at The species section is the largest in this book and includes descriptions of 705 individual species, based on the most recently published scientific information available. An additional 34 rare species are described in the appendix. A condensed summary of range and habitat is provided for each species. To save room, names of states are abbreviated. For example, California reads: CA. North, South, East, and West are also sometimes abbreviated and read, respectively: N, S, E, W. The biologic description provides a brief summary of the species behavior, diet, and/or ecology, where room allowed. The depths provided are approximate maximum recorded depths, although many fishes may be more common at shallower depths. The lengths given for each species are the approximate maximum recorded adult total length. Each account is accompanied by a large, full-color illustration of the species. Each fish is shown in living color, as it would appear in hand, or at the surface in clear water. While no two fish of the same species are exactly alike, the illustration intends to closely represent the species as one might observe it. Great care was taken to accurately portray the correct placement and proportion of anatomical features. All illustrations show the adult fish unless otherwise noted. The illustrations are presented in a "size relative" fashion, meaning those in the same genus and on the same page are shown at a size relative to the longest fish in the genus. Juveniles can be much smaller than adults; they are shown larger than size relative for clarity. Each illustration provides identifying anatomical and color features. All are shown facing left or from above with all fins displayed. The only exception is the presentation of right-eyed flatfishes, which are shown facing right. 15

3 16 Diversity and Classification Fishes comprise the most diverse group of vertebrates on Earth. There are currently over 32,000 known living species of fishes and many thousands of others that have become extinct in the 500 million years since the early fish ancestors first swam in the seas. Over 800 marine fish species live along the northwest Pacific coast of the United States, inhabiting bays, inlets, estuaries, rocky reefs, and rocky, sandy, and kelplined shores. These species range in size from the Whale Shark, which may grow to 50 feet, to the Arrow Goby, which as an adult grows to about 2.3 inches in length. Pacific Northwest coastal fishes also include species that represent the most primitive of ichthyofauna like the Pacific Hagfish to the most highly evolved forms, such as the Balloonfish. The scientific classification of fishes is, and will likely always be, an ongoing process subject to debate and change as new information unfolds. However, many scientists divide fishes into five recognized classes: Myxini, the Hagfishes; Petromyzontida, the Lampreys; Chondrichthyes, the Cartilaginous Fishes; Actinopterygii, the Ray-finned Fishes; and Sarcopterygii, the Lobe-finned Fishes. Of these five classes only the Lobefinned Fishes do not occur along the western United States. The table below shows how three representative fishes are classified in the three classes that occur along the western United States: Pacific Hagfish Whale Shark Southern Clingfish Kingdom: Animalia Animalia Animalia Phylum: Chordata Chordata Chordata Class: Myxini Chondrichthyes Actinopterygii Order: Myxiniformes Orectolobiformes Perciformes Family: Myxinidae Rhincodontidae Gobiesocidae Genus: Eptatretus Rhincodon Rimicola Species: stoutii typus dimorpha The jawless fishes Hagfishes and Lampreys are truly primitive. They lack true jaws, do not have paired fins, and exhibit a simple, cartilaginous skeletal structure. They have a single nostril located on the top of the head. Their form of locomotion is simple and eel-like. The simplicity of the jaws in this class of fishes limits them to rasping prey. However, this characteristic has not prohibited them from succeeding. Through scavenging and parasitizing, jawless fishes have survived, evolved, and prospered for hundreds of millions of years. The Cartilaginous fishes of the Class Chondrichthyes the familiar sharks, skates, and rays as well as the less familiar chimaeras are more structurally advanced than jawless fishes, even while lacking true bones. They have true jaws, and their nostrils are located on both sides of the head, generally under the snout. The skull and jaws are constructed of large single units, rather than multiple pieces as seen in the Ray-finned Fishes. Cartilaginous Fishes lack a swim bladder and most rely on large oily livers for buoyancy. Unlike jawless fishes, they possess paired fins: the pectoral and pelvic fins.

4 Another differentiating feature is that all cartilaginous species practice internal fertilization and the females produce either egg cases or live young. The largest and most diverse class of fishes is, by far, the familiar Ray-finned fishes of the Class Actinopterygii. This group possesses a bony, rather than cartilaginous, skeleton. Like the Cartilaginous fishes, bony fishes also possess true jaws. However, their jaws are composed of many small bones rather than large cartilaginous units. The skull is also a complex structure of small bones. The wide array of jaw and tooth types in this class has spawned a large variety of feeding systems, including biting, crushing, filter-feeding, sucking, picking, and scraping. Nostrils are found on the upper part of both sides of the head. Bony fishes usually have swim bladders, many of which are complex in structure. They also possess paired fins, but in some the pectoral and pelvic fins may be absent. Their methods of reproduction are wide and varied. Adaptations to Life in Water Living completely submerged in water presents a host of challenges. Fishes need to regulate the amount of salt and water in their bodies and extract dissolved oxygen from the water. Their senses are adapted to aquatic life. Beyond the basics of sight and smell, most fishes have a lateral line, a sensory organ that is highly developed to detect the minutest motions in the water. Fishes have also developed many ways to communicate with each other under water. Some grind their pharyngeal teeth, while others grunt by manipulating the air bladder. Some fishes have light-producing organs that they may use to locate each other or attract prey in the darkness. Water can be over 900 times more dense than air. Many fishes cruise through this dense solution by undulating the body, caudal peduncle, and tail to create forward thrust. Others move by flapping, fanning, or sculling the fins. Eels move much like snakes, winding their way through the water and over the bottom. Skates undulate their pectoral-fin lobes, whereas rays flap them. Many fishes have developed ingenious forms of locomotion. Searobins "crawl" across the bottom by "walking" with their free pectoral-fin rays. Remoras, while able to swim freely, have an adapted dorsal fin that forms a suction disk. This disk allows the Remora to "hitch a ride" on its host. Some fishes hardly swim at all. The Grunt Sculpin spends most of its life hopping and crawling along high-energy, wave-swept rocky bottoms. Identifying Fishes All fishes change shape and most change color as they develop. Juveniles can be drastically different from their adult counterparts. Adults of the same sex and species often have subtle differences. Numerous fishes are sexually dimorphic, meaning males and females are different in color and form. Many fishes change color and pattern depending on the time of day, time of migration, diet, depth, mood, or breeding phase. Some change color when they are hunting; others change color to appear intimidating. In addition, almost every fish changes color when it is caught, when it is in distress, or after it has died. 17

5 Depending on the subject at hand, identification can be an easy or daunting task. Some species of fishes are so unique that they do not resemble any other and are thus easy to identify. Others are so similar in appearance that only subtle nuances distinguish one from another. Even though the variety and changes in the color of fishes is great, observed colors and patterns are the most common tools used for identification. Below are several examples of commonly observed color patterns in Pacific coast fishes. dark lines radiating from eyes mottled pattern eye spot vermiculating pattern alternating pale and dark bars spots forming oblique bars dark, wavy stripes dark spots forming stripes along scales dark speckles irregular spots and blotches large, dark ocellated spot rosettes dark blotch on pectoral-fin base dark saddle banded pectoral fin banded caudal fin 18

6 When a fish is not identifiable by either color or pattern, the fish s anatomy can help to secure an identification. Shape, size, and placement of anatomical features vary from one species to the next and thus distinguish one from another. The following illustrations show the primary external features of several cartilaginous and bony fishes that are commonly used as tools for identification. Cartilaginous Fishes spiracle snout gill slits first dorsal fin second dorsal fin upper caudal-fin lobe notch Leopard Shark pelvic fin anal fin lower caudal-fin lobe pectoral fin convex margin concave margin ( ( pectoral-fin lobe (bluntly pointed) clasper (male) snout (pointed) Longnose Skate dorsal fins tail (thorny) nuchal thorns pelvic fin (bilobed) pectoral-fin lobe (bluntly rounded) thorns snout (blunt) pelvic fin tail skin fold spiracle snout (pointed) barb pectoral-fin lobe Diamond Stingray dorsal fins caudal fin tail Banded Guitarfish scapular thorns pelvic fin (straight margin) 19

7 Bony Fishes dorsal-fin spine opercular spine nape notch dorsal-fin ray caudal fin Stone Scorpionfish fleshy tabs pectoral-fin base second dorsal fin (soft) first dorsal fin (spiny) spiny knob cirrus pelvic fin band of oblique scale rows caudal peduncle anal-fin ray anal-fin spine snout maxilla Bonyhead Sculpin preopercular spine lateral line anal fin first dorsal fin (short-based) nape opercle second dorsal fin (long-based) scutes Bigeye Trevally snout preopercle pelvic fin tallest dorsal-fin spine scales on dorsal-fin base opercular margin pectoral fin (elongate) lateral line tallest dorsal-fin ray caudal fin (forked) Redtail Surfperch caudal fin (slightly forked) preopercular corner pelvic fin scales on anal-fin base 20

8 Lengths and proportions will also help in differentiating one fish from another. Total lengths are used in this book. To determine total length, measure from the tip of the snout or the tip of the lower jaw to the tip of the caudal fin. If the caudal fin is forked, press the upper and lower tips toward each other. The lengths provided in the accounts give the reader a general idea of how big a species may become. The illustration below shows positions of specific identifying features and indicates lengths and depth. fin origin opercular margin preopercular margin snout length fin tip fin lobe fin margin fin base upper lobe body depth midline preopercular corner chest pectoral-fin base abdomen fin base fin margin fin lobe total length lower lobe The overall shape of a fish s body can also help in identification. Shapes of the fishes presented in this book are in profile, as a fish would appear from the side. Proportions of a fish s depth relative to its length are important identifiers. A fish is said to be "deepbodied" when the measurement of depth is great relative to length, such as in the Popeye Catalufa. A fish is said to be elongate when its depth is small relative to length, such as in the Longnose Lancetfish. Some examples of profile are shown below. deep-bodied oblong similar upper & lower profiles elongate elongate and tapering eel-like 21

9 The cross-sectional shape of a fish is the shape of the body as it appears head on. A fish that is flattened from side to side is said to be laterally compressed. A fish that is flattened from top to bottom is described as flattened or depressed. Below are some simplified cross-sectional views. round oval laterally flattened/ compressed depressed Sometimes it is necessary to go further and count spines, rays, or scales to determine the identity of a fish. When counting spines and rays, the norm is to count anteriorly (front) to posteriorly (toward tail). Even if a spine is very small or directed forward, it is still counted. Additionally, if the last ray on the dorsal or anal fin is split to a unified base, it is still counted as a single ray. first dorsal-fin spine last dorsal-fin spine notch first branched ray last branched ray spiny portion soft portion fin base There are times when lateral-line scales need to be counted. These are counted from the first pored, lateral-line scale behind the opercle to the last pored scale that corresponds to the crease in the caudal peduncle when the caudal fin is moved from side to side. At other times, scales above the lateral line are counted. These are counted from the highest arch of the lateral line diagonally backward to the base of the dorsal fin. The habitat, geographic area, and depth range may also help in identification. For example, the blue-sided and blue-blotched forms of Blue Rockfish, Sebastes mystinus, have very similar appearances and features. However, their ranges barely overlap. When using depth as an identifier, it should be noted that many recorded depths are those taken by trawl or line. These records reflect the deepest point of the trawl or line and not necessarily the deepest level at which a fish may swim. Depth records may also reflect seasonal migrations or the preferred depth of juveniles or adults. 22

10 Conservation Many people have devoted countless hours to the conservation of our precious marine environments. It cannot be overstated how important it is to reduce, and possibly reverse, the harm due to run-off, pollution, destruction of habitat, and overfishing. If each person takes one small step toward conservation and preservation, the overall affect could be tremendous. Many fishes included in this book are currently Threatened or Endangered. The IUCN (International Union for Conservation of Nature) Red List of Threatened Species contains an evaluation of the extinction risk of global plants and animals. This information plays a significant role in guiding conservation activities and serves to monitor changes in the conservation status of species. Of the many fish species that are monitored, sharks are one of the most vulnerable. They have been heavily exploited and are largely misunderstood and misrepresented. Sharks grow slowly, have a long gestational period, and do not produce a large quantity of offspring. Therefore, it is very difficult for them to recover from the depletion they have suffered. On the positive side, there are several examples of population recovery due to conservation. One is the Giant Sea Bass. This enormous fish was severely overfished in the early 1900s. California passed legislation to prohibit taking this fish (with few exceptions) in 1981, and Mexico protected it in While it has made significant recovery, it is still listed as Critically Endangered on the IUCN Red List. The White Seabass was also in severe decline until laws restricted recreational catches and prohibited gill-netting this fish. Aided by captive breeding, this fish is now listed as Least Concern. We encourage our readers to educate themselves about the fishes they encounter. Most fishes have defense mechanisms meant to protect them from other fishes. Many fishes will defend themselves if threatened. A venomous fish would rather be left alone than use its precious venom. We also encourage our readers to Handle fishes gently. Please respect seasonal and catch limits. Obtain proper permits and licenses, as many states use sales revenues to fund conservation and enforcement. Do not release non-native fishes into any open body of water. Whenever possible, practice catch-and-release and respirate the fish before releasing it back into the water. Release native live bait back into the water. Dispose of waste properly. Anchor in designated areas. Participate in fisheries management by reporting tagged fishes. Use circle hooks to help prevent the fish from swallowing the hook. In short, if we care for fishes and their environment, they will be here in the future for us and future generations to admire. 23