l'''

~JO~JG tJ\I;JL)!h]Q! t ; I' F 0 Eo: / ~~~J

NATURAL HISTORY OF TWO-LINE EELPOUTS (BOTHROCARA BRUNNEUM, FAMILY ZOARCIDAE)

A thesis submitted to the faculty of San Francisco State University in partial fulfillment of the requirements for the degree

Master of Science in Marine Science

by

Lara Annette Ferry

San Francisco, California

June, 1994 NATURAL HISTORY OF TWO-LINE EELPOUTS (BOTHROCARA BRUNNEUM, FAMILY ZOARCIDAE)

Lara Annette Ferry San Francisco State University 1994

Two-line eelpouts were collected from two deep-sea sites in the Eastern North

Pacific in order to study feeding habits and morphology, age and growth, and reproduction and demography. Two-line eelpouts eat primarily shrimp-like crustaceans, and secondarily, juvenile zoarcids, probably of the same species.

Significant differences in diet between the two sites were found at the most general and the most specific levels of taxonomic characterization (!-test on PSI matrix; t = 26.6 and 14.5, tu=oos(2) = 1.96). Two-line eelpouts collected were a maximum of 14 years of age. A logistic growth model was the best fit to the data and predicts an asymptotic length of 690 mm total length. Instantaneous mortality estimates (z) ranged from 0.20 to 0.32 depending on considerations of variations in longevity. Two-line eelpouts have a relatively low fecundity of 215-

339 eggs per female, and appear to reproduce only once or, at the most, a few ·, times in their life. Age of first reproduction is relatively late in life, 11 years in females and B years in males. Best demographic estmates indicate this population is at or just exceeding a stable equilibrium with a long generation time of 10.13 to 14.60 years. ACKNOWLEDGMENTS

I would like to thank the Earl H. Myers and Ethel M. Myers

Oceanographic and Marine Biology Trust for partial funding of this project, and the David Packard foundation for travel support. Funding was also received through a US Navy grant to San Jose State University (Navy CLEAN Contract

No. N6247 4-88-0-5086). I would also like to thank David Griffith and Russ

Vetter from the National Marine Fisheries Service (Southwest Fisheries Science

Center, La Jolla, CA), Bob Lauth and the late Paul Raymore also of NMFS

(Alaska Fisheries Science Center, Seattle, WA), and Danny Heilprin of

Scientific Applications International Corporation, for allowing me to participate in research cruises and/or obtain specimens, and for providing data ne~ded for analysis in this project. In addition, I am grateful to Bob Leos and Jerry Spratt at California Department of Fish and Game for their assistance in trying to obtain specimens from commercial fishermen.

I would like to extend special thanks to Anne Summers and Lisa Smith­

Beasley of Moss Landing Marine Labs who helped to identify prey items; Allen

Andrews, Jocelyn Nowicki, and Kenneth Coale also of Moss Landing Marine

Labs for guidance with the radiochemistry attempts; and Mary Yoklavich of

Pacific Fisheries Environmental Group, and Guillermo Moreno from the

University of Sydney, Australia, for guidance in ageing the otoliths. Thanks to

Michael Foster and James Harvey who offered constant and much needed advice on statistics and experimental design, as well as Ross Clark, Matt

Edwards, James Downing, and Erica Burton (who cut up more than her share of

IV dead fish). I would also like to thank M. Eric Anderson from the J.L.B. Smith

Institute, Grahamstown, South Africa for his advice on zoarcids and guidance throughout my pilot study and thesis project

Lastly I owe a huge debt of gratitude to my advisor, Greg Cailliet, and my committee members, Ralph Larson, and Waldo Wakefield. Also to Lisa

Weetman who is responsible for getting me involved in this project from the beginning. I am ever grateful for the continued support of my parents, David

and Darleen Ferry, and also Michael Graham, who challenged me to ask the

most difficult questions and inspired me to always find the answer.

v TABLE OF CONTENTS

List of Tables vii

List of Figures viii

List of Appendices IX

Introduction 1 Materials and Methods

Collection of Specimens 4 Feeding & Morphology 5 Age & Gro\1/lh 9 Reproduction & Demography 12

Results

Feeding & Morphology 15

Age & Gro\1/lh 19

Reproduction & Demography 21

Discussion

Feeding & Morphology 23

Age & Grov.tth 26

Reproduction & Demography 29

Literature Cited 35

VI LIST OF TABLES

Table Page

1. Summary of trawl effort 43

2. Prey items found in guts 44 3. Potential prey at study sites 45 4. Life table for constant mortality 47 5, Life table for type I and type Ill mortality 53

vii LIST OF FIGURES

Figure Page 1. Map of study site 57 2. Otolith diagram 58 3. Total length frequency histogram 59 4. Fish size trends with depth 60 5. Length frequency histogram for fish used in feeding study 61 6. Cumulative prey curves 62 7. General Index of Relative Importance (IRI) 63 8. Specific IRI .. 64 9. Jaw morphology and relative prey sizes 65 10. Gut morphology 66 11. Length frequency histogram for fish aged in otolith analysis 67 12. Plots of otolith length, otolith width, and otolith weight

versus total length 66 13. Growth curves \ 69 14. Male maturity plots 70 15. Female maturity plots 71

16. Egg diameters and total fecundity 72

17. Cumulative maturity plot 74

18. Catch curve 75

19. Survivorship curves 76

viii LIST OF APPENDICES

Appendix Page

A. Trawl information 77

B. Otolith length and weight data 82

ix INTRODUCTION

Technological advances in deep sea research have provided scientists

greater opportunities for studying the unique creatures that live there and their

interactions with this environment. Because the deep sea has been difficult to

study, little is known regarding fish inhabiting this zone (Marshall 1979, Moyle

and Cech 1988). Many generalizations have been used to describe deep-sea fish and their survival mechanisms, without much evidence other than

morphological inference.

Eelpouts (Family Zoarcidae) are abundant and widespread residents of

North America's Pacific coast. The family has many members in the midwater,

deep-sea, and continental slope environments (Miller and Lea 1972, Eschmeyer

and Herald 1983). By studying the species that inhabit the continental slope, it

is possible to understand how species adapt to this transitional environment

between the "true deep sea" and more shallow marine environments. Two-line

eel pouts (Bothrocara brunneum) are common to this region, and are the largest

of the deep-sea eel pouts (Bayliff 1954, Bayliff 1959, Miller and Lea 1972, Hart

1980), making them a prime candidate for studies to increase our understanding

of ecology of fishes ofthis habitat. They are caught frequently in research trawls

on the continental slope and as by-catch in several commercial fisheries

(Eschmeyer and Herald 1983; Wakefield 1990). They are common at depths of

200 to 1500 m off California, and have been recorded as deep as 1800 m off

Oregon (Miller and Lea 1972, Hart 1980, Eschmeyer and Herald 1983). In spite

of their relative abundance, few ecological studies of two-line eel pouts have

been conducted.

1 Information regarding the diet of two-line eelpouts is scarce. Few researchers have studied the diet of any eelpout species, but many have reported gut contents associated with other descriptive work. These observations indicated eel pouts may consume a variety of benthic invertebrates

(Andriiashev 1954, Kliever 1976, Anderson 1980, McAllister et al. 1981,

Anderson 1982, Livingston and Gainey 1983, Mauchline and Gordon 1984,

Houston and Headrich 1986, Keats et al. 1987). Because prey is presumed scarce in the deep sea, fish living there are typically assumed to employ a generalist feeding strategy (Mayle and Cech 1988). Fitch and Lavenberg (1968) and Gotshall and Dyer (1987) suggested that two-line eelpouts eat almost any organism they encounter that will fit into their mouths.

Life span and growth rate of two-line eelpouts are unknown. Fitch' and

Lavenberg (1968) claimed that age could not be determined from otoliths of two­ line eelpouts, although they admitted information may be obtained using new techniques. Age and growth estimates determined from whole otoliths are available for only a few eelpout species. Other eelpouts appear to grow rapidly and, for species studied, may reach a maximum age of only five to eight years

(Levings 1967, blackbelly eelpout, Lycodopsis pacifica; Kliever 1976, persimmon eelpout, Eucryphycus (=Maynea) californicus; Anderson 1980, pallid eelpout,

Lycodapus mandibularis; Lancraft 1982, midwater eelpout, Melanostiqma pammelas). These researchers, however, did not validate age estimates.

Therefore, one can only speculate regarding age and growth of other eel pouts species.

Reproduction in two-line eelpouts has not been investigated. Studies of

2 other species indicate that eel pouts produce a few large eggs per female

(Gotshall 1971, Anderson 1980, La ncr aft 1982). Whether egg production is semi-annual, annual, or less frequent is debated among researchers (Levings

1967, Anderson 1980, Lancraft 1982). In benthic species, eggs may be laid in shallow burrows in sediment (Kendall et al. 1983, Silverberg et al. 1987), or in an eggmass guarded by the parents (Matarese et al. 1989). Because they are rarely collected in plankton nels, it is assumed larvae may become demersal or semi-demersal soon after hatching (Matarese el al. 1989). Consequently, larvae of only four species of this diverse family have been described (Kendall el al.

1983, Matarese et al. 1989). Larvae, presumably two-line eelpout, were found in an egg cluster extracted from sediment cores (Kendall el al. 1983). Such observations indicate this species may have a reproductive strategy similar to other eel pouts.

With such a lack of information regarding an abundant species, it was apparent that study of the two-line eel pout was necessary to learn more about how fish species have adapted to survive in the deep sea. The objective of this study, therefore, was to lest the following hypotheses regarding natural history of two-line eel pouts: 1) they are generalist feeders, and their diet consists of a variety of prey items reflecting the fauna described for each area; 2) two-line eelpouts, like other eelpouts, are fast growing, and due to their size, reach a maximum age slightly greater than those previously studied; and 3) female two­ line eelpouts have a low fecundity and reproduce only once or a few limes in their lifetime.

3 MATERIALS AND METHODS

Collection of Specimens

Specimens were collected from two different study areas: one off the

Columbia River mouth, off Oregon and southern Washington, and a second encompassing from Monterey Bay to a region just north of the Farallon Islands off central California (Fig. 1 ). Specimens were obtained from the following sources (Fig. 1, App. A): 1) Navy research cruises to the Gulf of the Farallones, including the Farallon Islands and Pioneer Canyon, by teams from Moss Landing

Marine Laboratories (MLML), Scientific Applications International Corporation

(SAIC), and Pacific Research Corporation (PRC) to study sites for the disposal of dredge spoils (July 1991, September 1991, February-March 1 992); 2) Trawls conducted by NOAA, National Marine Fisheries Service, Southwest Fisheries

Science Center (SWFSC) to develop habitat specific stock assessment methodology for west coast groundflsh, specifically within the Monterey

Submarine Canyon to 1200 m deep (November 21-25, 1992); 3) Trawls conducted on MLML cruises between 1000 and 2500 m in the Monterey Bay region (October 1991, 1992, 1993); 4) Incidental catches in sablefish traps and deep water trawls from'commercial fishermen from Monterey and Moss Landing ports (July-December 1993); and 5) Trawls conducted by NOAA, National

Marine Fisheries Service, Alaska Fisheries Science Center (AFSC) to survey demersal groundfish from 200 to 1400 m depth from Natinat Canyon,

Washington to the Columbia River mouth (October-November 1992, 1993).

Specimens were collected using several types of trawl gear (App. A).

Sta11.dard commercial otter trawls of varying dimensions were used most

4 frequently. These included a standard Aberdeen (North Sea commercial trawl) otter trawl was used off the 108ft commercial fishing vessel (FN) GOLDEN

FLEECE, chartered for use in the Gulf of the Farallones. This net had a 29.7 m headrope, 35.5 m footrope, 1.5 x 2.1 m steel doors, and 5.5 x 16.15 m diameter mouth. To prevent fouling, rubber rollers were attached to the footrope and floats to the headrope. A second otter trawl, usually described as a 400-Eastern bottom trawl, of similar dimensions, was used in Monterey Bay by the NOM research vessel, (RN) DAVID STARR JORDAN. A standard research beam trawl was used on the RN POINT SUR in both the Gulf of the Farallones and

Monterey Bay that had a mouth diameter of 2.1 m and a bag length of 6. 7 m.

Standard commercial otter trawls were used by the FN CC & GLORIA and the

FN MARIAN ANN in and outside Monterey Bay. A poly-noreastern botl

Feeding and Morphology

For diet analysiE;, area of study was divided into two separate sites: a central California site, and a Columbia River mouth site (Fig. 1). Specimens from both sites ~ere either dissected immediately, preserved intact in 10% formalin and stored in 40% isopropyl alcohol, or frozen upon capture.

Preliminary results indicated that digestion was extremely slow and freezing was

adequate to ensure prey items were retained in state similar to that at time of

capture. Total length and sex were recorded for each specimen.

5 Guts (the single cardiac stomach and intestine) were removed, everted, and flushed clean with water. In a pilot study, I found that stomachs rarely contained prey items, so it would be necessary to include intestinal contents in my analysis. McDonald et al. (1982) also observed that emptying the entire gastrointestinal tract was necessary to provide adequate data to describe diet of ocean pouts (Macrozoarces americanus). Contents were preserved in 1D% formalin, stored in 70% ethanol, and identified to lowest possible taxon.

Identifications were made using a dissection microscope and available taxonomic literature (Schmidt 1921, Butler 1980, Kathman et al. 1986, Kosloff

1987, Brusca and Brusca 1990).

Prey items were quantified in each gut according to Cailliet et al. ( 1986 ).

Number and volume of each prey type consumed was estimated based o"n undigested remains. Complete digestion, as defined by McDonald et al. ( 1982), was the point at which a prey item was no longer recognizable. This definition was used to differentiate identifiable prey items from digested material. Hard parts of prey items remaining were considered valid for use in identifying digested prey items. Digested material was only used as a description of gut contents if no other identification could be made. Items was grouped by general taxon and lowesi possible taxon to compare diet within and between regions.

Items that occurred only rarely and appeared in the gut presumably because

they were accidentally ingested with other prey items (e.g. one ophiuroid, a

single unopened bivalve), were not included in the analysis.

Cumulative prey curves were used to determine if a sufficient number of

guts had been analyzed from each site to accurately describe diet (Cailliet et al.

6 1988). To avoid bias caused by the order in which guts were analyzed, the order of gut analysis was randomized five times, and the mean cumulative number of prey taxa found for each consecutive gut plotted. To determine if variability decreased with increasing sample size, 95% confidence intervals were calculated for every tenth (central California fish) or twentieth (Columbia River mouth fish) gut.

Indices of relative importance (IRI; Pinkas et aL 1971) were used to characterize diets at each site. These were calculated by pooling gut contents from each site, and calculating percent number (%N ; number of each prey type divided by the total number of prey of all types), percent volume (%V; volume of each prey type divided by the total volume of prey of all types), and percent frequency of occurrence of each prey type (%FO ; number of guts contai_f'ling that prey type divided by total number of fish analyzed). TotaliRI values were calculated using the formula: [(%N + %V) x %FO] x 1 DOD (Pinkas et al. 1971 ).

Index of relative importance diagrams were constructed for comparing prey items at the most general level and at the most specific leveL A simplified Morisita's

Index of Similarity (Krebs 1988) was used to compare total IRI values for each general and specific pr'ey item.

A Percent Similarity Index (PSI ; Silver 1975) was used to compare %N of ' prey items within and between sites. The percent similarity among eelpouts within each site was calculated by constructing a matrix to compare each eelpout as a sample unit to all other eel pouts from that site using the following formula:

7 PSI ~£[(min piA.U +min pi 8,1,2 +... min pix.1•2 )+(min piA.1,,min pi 8 ,1,:.+ ... min pix.1.3 )+ ... 1

(min piA,,,vmin Pis,tv + ... min Pix,1,v )+ ... (min pi•.

where x is the number of prey items (pi), and the minimum proportion of each prey item (A, B, ... X) is calculated between predators 1 and 2, 1 and 3, and 1 and

Y, the Yth predator being the last examined and (Y -1) and Y being the last predators to be compared so that all predators are compared to all other predators without repetition (all possible permutations). A mean PSI was calculated for the n permutations. At-test was used to compare mean PSI values between sites.

Similarly, eelpouts from the central California site were compared to eelpouts from the Columbia River mouth site individually using the following formula:

PSI overall=~~ [(min pi •.1 ,1 + min pi8 ,1,1+... min pix.1,1 ) +(min piA,1,zmin pi8 ,1.z + ... min Pix.1.z)+ ... (min piA,v,zmin pis.v.z +... min pix,v,z)],

where the minimum proportion of each prey item (A, B, .. .X) is calculated between predators 1 and 1 from each site, in which Y is the number of fish analyzed at the first site and Z is the number of fish analyzed at the second site so that all predators from each site are compared to all predators from the other site without repetition. A mean overall PSI between sites was calculated for the n values. A between site PSI was also calculated using pooled %N for each

8 site, where all fish are pooled together into a single sample unit and %N of each prey item calculated.

Prey abundance was qualitatively described at each site using data from other studies (Pearcy et al. 1977, Pereyra and Alton 1972, Pearcy et al. 1982,

Wakefield 1990, SAIC 1992). Potential prey items were identified based on size relative to the mouth size of an average two-line eelpout. Abundance estimates for these items from the two sources were used to evaluate whether the item could have been selected or avoided by two-line eel pouts.

Feeding morphology of specimens from off central California and the

Columbia River mouth was also investigated. Features of the mouth, gills, and digestive tract were described to determine how each contributes to feeding and how they might function together for prey acquisition, retention, and assimilation.

Specific parts, such as teeth, gill rakers, intestine, and stomach were described qualitatively to ascertain their respective role in feeding. Gape and cleft (Cailliet et al. 1986) were measured to the nearest millimeter and compared to the maximum reported size of identified prey items.

Age and Growth

Fish collected frbm all sources were used in age and growth analysis.

Sex and total length to the nearest millimeter were recorded for all fish used in analysis. Standard length was also measured for a subsample of fish to determine variation between the two measurements. Wet weight was also

recorded for a subsample of fish.

Sagittae (henceforth referred to as "otoliths") were removed from fresh

and frozen specimens and measured from anterior to posterior at the longest

9 point just below the sulcus and across the widest section of the otolith (Fig. 2,

App. B), and resulting length and width plotted against fish total length. Otoliths were also dried to constant dryness (approximately 48 hrs. at 85-95° F), weighed to nearest 0.001 g (App. B), and otolith weight plotted against fish total length to determine which had a better predictive relationship (determined by r2 value) for determining fish length from otolith size (Boehler! 1985).

Otoliths were prepared for reading following techniques outlined by

Chilton and Beamish (1982). A single otolith from each specimen was embedded in epoxy resin and mounted on a card for sectioning with an lsomet low speed saw, as recommended by Beamish (1979) for greater accuracy in reading. Otoliths were mounted sulcus region upward to prevent degradation of the nucleus by the cutting procedure. Otoliths were sectioned in frontally (Fig. 2) because that direction yielded greatest resolution of rings. Sections through the nucleus of the otolith were mounted on microscope slides using a liquid cover slip that is allowed to harden around the section for 24 hours, and ground and polished using successive grades of grinding paper.

Sections were graded as poor, moderate, or good readability. Moderate and good sections were read for analysis using transmitted light microscopy.

Each reading consisted of ccunts along several axes to estimate age. Otoliths were aged two separate times, in order from smallest to largest (by fish TL), so younger fish were aged first and location of the first annulus could be

established. Otoliths were aged a third time in random order to check for reader

bias caused by ageing them in order. Average percent error (APE) was

calculated to determine precision of age estimates (Beamish and Fournier

10 1981 ). Because the age estimates varied little from reading to reading, a mean age was used as a measure of fish age.

Fishparm ( Saila et al. 1988) was used to fit growth models to the age and

length data and determine which had the best predictive value. Gompertz,

logistic, and von Bertalanffy models were fit to the data and plotted. A linear

model was fit to the data using Delta Graph Professional (Delta Point, Inc.

1992). Mean square error and r2, provided by Fishparm, were used to

objectively evaluate which model best described the data. Mean asymptotic

length ( L00 ) predicted by the models was also used to subjectively evaluate the appropriateness of each model for describing two-line eelpout growth.

Variations on possible longevity, given the estimates of L00 provided by the various growth models, were considered and three alternative longevities were calculated. These correspond to longevity estimated from fish aged in this

study, longevity estimated by extending a mean growth rate to the L00 predicted by the logistic growth model and extrapolating an age, and longevity estimated

by applying a mean growth rate to the L00 predicted by the Gompertz growth model. The parameters predicted by the von Bertalanffy model were considered

unrealistic.

Male and'fema!e growth rates were compared to determine if they were

significantly different Kappenman ( 1981) provided a technique to compare

growth models fit independently to male and female age data. Two models are

created, one that is used to describe the growth of the entire population, and a

second that is used to describe the growth of males and females separately. By

comparing these two models fit to the data collected, one can determine which

11 describes the data best, and conclude if growth rates between males and females are different

Reproduction and Demography

The reproductive condition of all specimens collected was categorized visually when sex could be determined. Males were subjectively grouped as

immature, mature, or spent, and females were grouped as immature (eggs too

small to measure), small eggs (eggs to 1.00 mm diameter), medium eggs (1.01 -

4.00 mm diameter), large eggs (4.01 and larger eggs), or spent. A more detailed

assessment of reproductive condition was conducted for a subs ample of

specimens (subsamples represent at least 20% of the original number of fish)

that were weighed to the nearest 0.01 g. Gonads from these specimens were

removed, blotted dry, and weighed to the nearest 0.0001 g. The number' of eggs

per female was counted for a second subsample of specimens. Size of eggs per

ovary was determined by measuring egg diameter of 50 eggs randomly selected

from each ovary (Lancraft (1982) noted that shrinkage of zoarcid eggs was

negligible in preservative). Eggs were selected for measurement by spreading

them along the bottom of a petri dish marked with a numbered grid. All eggs in a

randomly selected square were measured under magnification using an image

analyzer (Bausch and Lomb Monozoom 7 microscope attached to a Macintosh

IICX equipped with Macintosh IMAGE software).

Gonad indices were calculated using the formula: gonad weighU(total

length)3 x 108 (Cailliet et al. 1986), and were used to validate the visual maturity

estimates. All eggs per ovary were counted and used to estimate fecundity.

Age of first reproduction was estimated by comparing total length of individuals

12 containing eggs to an age-length relationship curve for two-line eel pouts estimated from age and growth data collected in this study. The presence of medium eggs was used as an indication of approaching maturity. The youngest individuals containing large eggs were used to represent age of first reproduction. Cumulative maturity was estimated by calculating the percent of females containing medium eggs, large eggs, and spent ovaries for designated size categories (20 mm increments of fish total length) and plotting it against those size categories.

Longevity was used to estimate instantaneous mortality (z) using the methods outlined in Hoenig (1983). Using data from fish, mollusc, and cetacean populations, he developed a regression model and created the predictive equation: ln(z) = a + b ln(tm ..l• where a and b come from the model and !'"'"is the maximum age attained by the population to which it is to be applied. He

noted that this procedure for estimating z can be used even when the sample is not representative of the population. It was assumed that there was a stable age

distribution of two-line eelpouts and that fishing did not seriously affect the

population.

Mortality rates e'stimated using Hoenig's (1983) technique were compared

to rates estimated using a more traditional catch curve (Ricker 1975). Number

of fish captured for each age was calculated by estimating ranges in total length

associated with each age and assigning ages to all length data collected for

which fish age was not estimated directly. Size peaks in a length frequency

histogram of all fish collected were used to help identify possible age classes

and refine the range of total lengths associated with each age (MacDonald and

13 Pitcher 1979, Nielson et al. 1983). The natural log of the number of fish caught of each age was plotted against fish age (also referred to as time, t), and the resulting slope used to estimate mortality.

Survivorship (lx) was calculated using the equation: lx = lx_1 x e-z Survivorship curves were created using lx plotted against fish age (x) over the life span of the fish. (Cailliet 1992). Variations in longevity and resulting mortality were used to create a range of probable survivorship.

A life table was created to estimate demographic parameters of generation time (G), and intrinsic rate of population increase (r). Variations in possible values of longevity and mortality (z) were considered in constructing the table so that a range of reliable estimates for each parameter could be calculated. Survivorship (lxl and reproduction (mx) were used to calculate these parameters. It was assumed that once females reached sexual maturity the potential number of female offspring per female (mx) was constant. The mean fecundity divided in half then multiplied by 75% (an estimated survival rate) was used to estimate this value. The survival of eggs once laid was estimated to be

75% using literature on more extensively studied species (i.e. salmon; Morrison et al. 1985, MacKenzie and Moring 1988, Scrivner 1988). This was considered to be a conservative but reliable estimate. A line fit to the cumulative maturity plot was used to predict the percent of mature females (%m) at each age. Both semelparity and iteroparity were considered in estimating %m and the corresponding demographic estimates. In the case of iteroparity, %m was additive from age group to age group because it was assumed that mature females continued to reproduce annually. For semelparity, %m for each age

14 group was distinct from %m in other age groups since each female is assumed to reproduce only once.

RESULTS

Feeding and Morphology

A total of 542 fish was collected from the two sites (Fig. 3), and there appeared to be no trend in size of fish with depth (Fig. 4, Table 1, App. A). All fish collected from off central California (n = 55) were analyzed, while a subsample (n = 173) of fish from the Columbia River mouth region were randomly selected from the total collected until it was believed that a sufficient number had been analyzed (Fig. 5). Cumulative prey curves were asymptotic at

45 guts for eel pouts off central California and 100 guts for eel pouts from the

Columbia River mouth and confidence intervals tightened around both these points (Fig. 6), verifying that the number of guts analyzed was more than sufficient.

Guts (stomach + intestine) were rarely empty, but often contained

"digested material". Thirty-one of 228 guts (14%) examined contained only this materiaL A greater proportion of guts contained this substance in combination with identifiable prey. 'Approximately 15% of guts contained more than one of the same prey item, however, only 11 guts (5%) contained more than one prey species.

A total of nine different prey items (Table 2) from three phyla was identified in eel pout guts from both sites. Prey items consisted primarily of five types of crustaceans: Holmsiella sp.(possibly H. anomala), Heptacarpus sp.,

Goathophausia gj_g§§_, Eucopia sp., and an unidentified mysid. The majority of

15 crustaceans, however, could not be identified as specifically. A large portion of the gut contents was comprised of this more general category. Crustaceans were found in guts from eel pouts of all sizes. Fish remains (Ph. Vertebrata) were less common than crustaceans (Fig. 7). All identifiable fish prey were small zoarcids, possibly juvenile two-line eelpouts, that were 80-90 mm TL. Fish prey were present in eel pouts as small as 27 4 mm but most common in individuals 360-490 mm TL. Mollusc remains in fish from the central California site consisted of four cephalopods, probably of two different species.

Cephalopods were not found in fish from the Columbia River mouth.

Because specific identification was rare, it was difficult to identify trends in prey consumption with depth. Crustacean prey were found in eelpouts captured from all depths (618 - 1620 m). Similarly, prey identified as mysids, possible

Gnathophausia, and possible Eucopia, were found in eelpouts captured from

618 to 1324 m depth. Heptacarpus sp., however, was found only in eelpouts captured from 618 to 896 m, while Holmsiella sp. was found only in eel pouts captured from 1072 to 1324 m. Cephalopod prey was found only in eelpouts captured at 750-800 m depth and fish prey was found only in eelpouts from

1018-1324 m, with the'€xception of a single occurrence of fish prey recovered from a specimen captured at 702 m depth. It is unknown, however, how large an

area two-line eel pouts utilize for foraging, and at what depths these prey might

have actually been consumed.

At the most general level (Fig. 7), the diet at the two sites was 74% similar

according to a simplified Morisita's Index of Similarity using total %1RI values. A

PSI using pooled %N indicated a 84% similarity in diet between the two sites,

16 however, a mean overall PSI indicated only a 63% similarity (SO= 46.9). At the most specific level (Fig. 8), the diets were 51% similar using total %1RI values,

47% similar using pooled %N of each prey item, and 39% similar (SO= 47.3) using mean overall %N. The Columbia River mouth site was slightly more diverse in number of specific items identified.

Within the central California site, mean PSI values of 57% (SO= 47.8) and 36% (SO= 46.7) for general and specific levels of prey identification, diet, therefore is highly variable from eelpout to eelpout. This is to be expected when fish consume only one prey item at a time. Similarly, mean PSI values are 70%

(SD = 43.8) and 43% (SO= 46.6) for general and specific levels of prey identification at the Columbia River mouth site. Diet, therefore, is more similar within the Columbia River mouth site. The mean PSI values had equal :' variances and were significantly different between sites at both the general and specific level (t = 26.6 and 14.5, ta=0.05(2l = 1.96; Zar 1984). Fish and invertebrate megafauna! communities were similar at both sites

(SAIC 1992), indicating potential prey abundance also was similar at both sites

(Table 3). Echinoderms were the most abundant group at the Farallon Islands and crustaceans (due i'n large part to the high occurrence of tanner crabs) had the highest ove6311 biomass, conversely, echinoderms had the highest biomass

off Oregon, but crustaceans were still an important group (due, again, to the

presence of tanner crabs). Sea anemones and sea stars were among the most

common groups in both California and Oregon, and gastropods ranked third in

biomass in both areas (SAIC 1992, Pereyra & Alton 1972).

In light of the prey items identified above, however, it is likely that two-line

17 eelpouts are not feeding on the benthic fauna, but on benthopelagic fauna.

Unfortunately, no studies have effectively quantified the communities existing within a meter of the substrate making it impossible to assess potential prey in this zone. Pearcy eta!. (1977) give a rough idea of the abundant and rare species they encountered off the coast of Oregon. These may be potential prey

items for the two-line eelpout (Table 3).

Two-line eelpouts possess needle-sharp villiform teeth in unorganized

rows on the premaxilla and dentaries (Fig. 9). The lower jaw is underslung and the upper and lower jaws do not meet completely leaving a gap exposing the teeth. They also have a row of teeth on the front of the vomer and progressing

along the sides. These may be palatine teeth, however palatine teeth are supposed to be absent in this species. These teeth were present in all :'

specimens collected. Plates with two rows of densely packed teeth are located

directly over the gill rakers, which also have tooth like projections. The gill filaments were long and fairly fine.

The gape ranged from 52 to 58 mm and the cleft ranged from 47 to 53 mm for fish 557-593 mm TL (n = 3). They were equivalent to approximately 10% of

the total length of the fish (Fig. 9). The ratio of gape and cleft size to body size

appeared to var)' little for all fish collected. The maximum reported widths of

Heptacarpus, Holmsiella, and Eucopia fit easily into the open mouth (Fig. 9).

Gnathophausia grows much larger than the maximum gape or cleft but those

found in the stomach were smaller individuals, probably juveniles. Small

eelpouts consumed were larger than the maximum gape or cleft. The buccal

cavity, however, is large and capable of expansion, and the branchiostegal rays

18 are held together loosely by a large flap of skin indicating that the branchiostegal basket is capable of massive expansion. Eelpouts in the stomachs of fish were folded over themselves to fit in the space available.

The digestive tract, observed for all fish analyzed, consists of a single cardiac stomach and intestine with little variation among fish (Fig. 1 0). The exterior of the stomach is darkly colored as is the lining of the peritoneum. The

stomach lining is rugose and the stomach is thick-walled. Full stomachs were observed expanded to three or more times their relaxed (empty) size. The intestine is translucent and coiled irregularly within the coelom. In the specimens measured (n = 3), it is equivalent to 95% of the total length of the fish, which appears to be consistent among all fish collected.

Age and Growth

A total of 242 otolith sections of moderate to good readability was aged for analysis. Sizes of fish analyzed ranged from 129 mm to 606 mm TL (Fig. 11 ).

Of these, females ranged from 1 90 mm to 590 mm, and males ranged from 179

mm to 606 mm. Fish smaller than 200 mm TL generally could not be

categorized as male or female.

Of age estimate's, the third, random reading agreed with at least one

estimate from the previous two ordered readings in 167 out of 240 (70%)

otoliths. Age estimates among all three readings differed by only one year in

93% of the otoliths. All three age estimates were identical in 92 out of 240

(38%) otoliths. Average percent error was only 1% among all three readings.

Otolith length and width were both significantly (p<0.001 ; Wilkinson

et aL 1 992), and linearly related to fish total length (Fig. 12a, 12b). A line fit to

19 otolith length data provided the equation: y = 0.006x + 0.94 to describe otolith growth, with r2 = 0.82. A line fit to otolith width data provided the equation: y =

0.003x + 0.35 to describe otolith growth, with r2 = 0.88. Otolith length and otolith weight appear to be equally useful for predicting fish length. Otolith weight is less useful for predicting fish length (Fig. 12c). An exponential curve was the best fit to the data and provided the equation: y = 0.00000008x2.14, with r2 = 0.71.

Size at age plots indicated a nearly linear relationship between age and total length in both males and females (Fig. 13). Logistic, von Bertalanffy, and

Gompertz growth models appeared to fit equally well, although predictions associated with the models varied greatly. The logistic model fit the best since

mean square error was the lowest and r2 was the highest by 0.001. The.t00 predicted by the logistic model, 694.5 mm TL, was the most realistic and corresponds with the maximum reported length for a two-line eelpout 660 mm TL

(Hart 1980). A mean growth rate extended to this size corresponds to a

longevity of 18 years. Similarly, the L00 predicted by the Gompertz growth model corresponds to a longevity of 22 years when a mean growth rate is extended to that size. These both exceed the maximum age of 14 years attained by

specimens in this study.

It was det'ermined that a single logistic model fit to all data combined

described the data better than two separate models fit to male and female age

data independently. Therefore, it could be concluded that there was no

difference in logistic growth models fit separately to male and female age data

and that there was no sexual dimorphism in growth.

20 Reproduction and Demography

Apparently-mature gonads in males were observed in individuals 383-606 mm TL while immature testes were observed in individuals 179-525 mm TL (Fig.

14 ). Five apparently-spent males were collected that ranged from 478-565 mm

TL. Gonad indices of immature testes were 0-0.1 0 and mature testes were 0.17-

0.62.

Four females were captured that were considered spent, these females ranged from 530 to 557 mm TL (Fig. 15). Only one specimen, 522 mm TL, was captured with large eggs. The gonad index for this specimen was 27.7.

Females often contained eggs in an immature state (small and medium eggs).

Individuals containing medium eggs ranged from 443 to 617 mm TL. Gonad indices for this category ranged from 0.83 to 1.83. Individuals containing small eggs were 385-604 mm TL and gonad indices for this category were 0.20-0.74.

Immature ovaries were observed in individuals from 256 to 501 mm TL.

Egg size within an ovary was remarkably constant (Fig. 16). There appeared to be no relationship, however, between fish size and egg diameter.

The eggs from the single mature individual contained averaged 4.15 mm (SE =

0.05) in diameter. There were many females larger than the 522 mm specimen that contained small eggs. The 617 mm female was the only female observed with eggs of two different size categories, small and medium. Even under microscopic examination, small primordial eggs were not observed in ovaries containing eggs of other size classes. The larger eggs in the 617 mm specimen appeared degenerated. Fecundity ranged from 215 to 329 eggs per female and was not dependent on female size (Fig. 16).

21 A cumulative maturity plot was used to estimate age of first reproduction

(Fig. 17). The single female specimen with large eggs was used to represent female maturity. A total length of 522 mm corresponded with an age of approximately 11 years. Females began to possess medium eggs at 458 mm

TL, a size that corresponds with approximately 9 years of age. Females with medium eggs were considered to be approaching maturity. The smallest male observed with apparently-mature testis was used to estimate age of first reproductive contribution for males. A total length of 383 mm corresponds to an age of approximately 8 years.

Instantaneous mortality estimates (z) ranged from 0.20 to 0.31, with increased longevity resulting in decreased mortality (Table 4). A catch curve did not help to refine mortality estimates (Fig. 18). The slope appears very close to zero. Zero mortality is unlikely, and such a curve indicates a sampling bias probably occurred. Survivorship curves most closely resembled a type II curve

(Fig. 19). The number of younger individuals declined at a more rapid rate than the number of older individuals, but mortality rate is constant.

Using these variations in longevity and mortality, best demographic estimates of generatioi'1 time (G) were 10.1 to 11.0 years in the case of semelparity and.-11.3 to 14.1 years for iteroparity (Table 4). Intrinsic rate of increase (r) estimates ranged from 0.09 to 0.20 in the case of semelparity and

0.17 to 0.27 for iteroparity, indicating that this population is at a stable equilibrium or increasing slightly. Net reproductive rate (R0 ), ranged from 2.6 to 9.0 in the case of semelparity and 7.17 to 44.1 for iteroparity.

Non-constant mortality rates were also considered in estimating

22 demographic parameters. Using a longevity of 18 years as a model (Table 4b), probably the most realistic given the maximum reported length for the species, two- and three-fold increases in mortality in the early years (a type Ill mortality) reduced r to values closer to 0.0, a value indicating a truly stable equilibrium

(Table 5). This situation is reasonable since possible cannibalism was observed. Increasing mortality two- to four-fold in later years (a type 1 mortality), as the catch curve indicated may be occurring, did not have much effect on r values (Table 5).

DISCUSSION

Feeding and Morphology

Two-line eelpouts fed primarily on deepwater crustaceans. Although some crustacean species were identified only at one site, all were deepwater forms. Eucopia and Holmsiella are deepwater crustaceans well within the described depth range for two-line eelpouts. Eucopia is presumed to spend time on the bottom, but some species undergo diurnal vertical migrations of 400 m

(Kathman et al. 1986). Gnathophausia is bathypelagic, and inhabits a vertical range overlapping that of two-line eelpouts (Kathman et al. 1986). Species of

Heptacarpus vary in habitat, but some are deepwater forms (Butler 1980).

Because items in the stomach were rare, the likelihood of fish feeding in the net was low (Hopkins and Baird 1975).

Fish prey that could be identified as small zoarcids may have been small two-line eelpouts. Other possible identifications for these small fish are other members of the genus Bothrocara, mainly the soft eelpout, Bothrocara molle, and species of Lycodapus. The soft eelpout tends to inhabit much deeper

23 ------

depths, however, than the two-line eelpout (Hart 1980, Pearcy et al. 1982),

deeper than the depths from which fish containing eel pout prey in their guts

were captured. The blackmouth eelpout, Lycodapus fierasfer. inhabits a depth

range that overlaps that of the two-line eelpout, but is considered rare (Miller

and Lea 1972). It has a large gill cover and an upturned mouth (Eschmeyer and

Herald 1983). The available specimens lacked the features necessary to

confirm their identification.

Benthic fauna prevalent in guts of other eel pout species (Andriiashev

1954, McAllister et al. 1981, Anderson 1982, Livingston and Gainey 1983, Keats

et a!. 1987) was absent in two-line eelpout diet. Softer-bodied invertebrates

(e.g_ annelids) may have been rapidly digested. The presence of annelids in

stomach contents of other eelpout species, however, indicated such prey were

identifiable following some degree of digestion (Andriiashev 1954, McAllister et

al. 1981, Anderson 1982, Livingston and Gainey 1983, Houston and Haedrich

1986). Such items may be more important in the diet at other times of year when

eelpouts could not be collected. It is also possible that two-line eelpouts are

feeding in the benthopelagic layer rather than on the benthos. Wakefield (pers.

comm.) reports that twb-line eelpouts are found hovering within approximately .5

m of the substrate in ROV (remote operated vehicle) footage shot off central

California.

Potential benthic prey appeared to differ from items found in eel pout guts.

Off central California, echinoderms were the most abundant fauna collected in

surveys (SAIC 1991 ). Crustaceans had the highest overall biomass, but this

was due to the occurrence of tanner crabs, Chionecetes tanneri, that are not

24 considered prey items. Echinoderms had the greatest biomass off Oregon

(Columbia River mouth region), but crustaceans were still abundant (due, again, to the presence of tanner crabs ; Pereyra and Alton 1972). Inappropriate sampling technique or net avoidance may have caused shrimp-like crustaceans and other benthopelagic animals to be underrepresented in surveys used to estimate potential prey. Gastropods ranked third in biomass, and cnidarians were abundant at both sites (Pereyra and Alton 1972, SAIC 1992). The abundance of gastropods and cnidarians at the central California site at times when eel pouts were collected indicates that two-line eelpouts are stenophagic and may be capable of prey selectivity. Mauchline and Gordon ( 1986) categorized fish like the two-line eelpout as opportunistic predators which regularly exploit a preferred prey taxon.

Two-line eelpouts appear to be well adapted for consuming highly mobile prey, such as crustaceans or small zoarcids. The pectoral fins are large and rounded, as is characteristic of roving predators (Moyie and Cech 1988). A double lateral line, elongate body, and deeply pitted head probably enhance mechanoreception (Mayle and Cech 1988) for detecting moving prey. The large mouth and long jaw are appropriate for snatching detected prey out of the water column. The many small teeth may be adapted for holding prey, like a struggling crustacean, as it is manipulated within the oral cavity.

The digestive tract, similar to that observed in herbivorous fishes (Horn and Messer 1992) or jellivores (fish that eat gelatinous prey ; Cailliet and

Ebeling 1990), may be particularly useful for obtaining a maximum amount of nutrition from prey items ingested. The very long intestine indicates that prey

25 are probably retained in the system for extended periods of time. Food is likely digested very slowly since prey items could often be identified, at least to the most general levels, even when found at the end of the intestine. The high number of two-line eelpouts that had identifiable prey in their gut indicates that they probably feed infrequently.

The olfactory system, highly advanced in some deep-sea fishes (Marshall

1979, Bone and Marshall 1982, Gage and Tyler 1991 ), may not be as important for two-line eel pouts, because they rarely are observed in video footage of baited traps. Smith ( 1985) documented a single zoarcid feeding at a baited trap

2-3 days after the bait was placed on the substrate and after 90% of the bait was consumed by other predators. It appeared unaffected by camera lights or other species present. Based on the small amount of food remaining, it is questionable whether olfaction could have been responsible for attracting the eelpout.

If we are able to keep this species alive in captivity in the future, I recommend study of the morphology and associated feeding behaviors of the live two-line eelpout. Gut evacuation and prey preference studies would be extremely useful in further understanding the feeding ecology of this species.

Any new information will help researchers to better understand feeding and predation in deep-sea and continental slope fish.

Age and Growth

The maximum age attained by the largest specimen in this study indicates that two-line eelpouts may not exceed an age of approximately 14 years. The asymptotic length of 695 mm TL predicted by the logistic model is the most

26 realistic and is consistent with the maximum length found in any scientific literature or other studies (Hart 1980; W. Wakefield, pers. comm., W. Pearcy, pers. comm.). An asymptotic length of 859 mm predicted by the Gompertz growth model seems unrealistic. Growth models predicting an asymptotic period of growth might be improper for analyzing the age structure of fish populations like two-line eelpout.

Fifteen years as a maximum age is considerably lower than longevity estimates for taxonomically unrelated species commonly inhabiting the same region as the two-line eelpout. Dover sole (Microstomus pacificus) age estimates exceed 50 years of age (Hunter et al. 1990) and thornyhead species

(Sebastolobus altivelis and S. alascanus) exceed 100 years (Klein, in press).

These long-lived species apparently have developed a different life histqly for surviving in this deep-sea environment.

Two-line eelpouts appear to live longer than their shallow water counterparts. Longevity estimates for other species that have been studied range from five to eight years (Levings 1967, blackbelly eelpout; Kliever 1976, persimmon eel pout; Anderson 1980, pallid eel pout; Lancraft 1982, midwater eel pout). This extensibn in longevity of congeners from shallow to deep water environments is 'mirrored in the flatfishes and the rockfishes (Bennett et al. 1982;

Hunter et al. 1990, Watters 1993).

Two-line eelpouts appear to grow at a rate of 4 to 5 em per year throughout their lives. This rate is slightly more rapid than reliable estimates for other eelpout species, who appear to grow at approximately 2.5 em per year

(Anderson 1977, Kliever 1976). Sablefish (Anoplopoma fimbria) grow at a

27 ------

comparable rate of 4-5 em per year (Cailliet et aL 1986), but reach an asymptote

in growth rate that is sustained for much a longer period. Dover sole and

thornyhead grow much more slowly (Hunter et aL 1990; Klein, in press).

However, all conclusions depend upon the validity of the age estimates.

Unfortunately, age estimates for the two-line eel pout could not be validated. Tag

and recapture methods are not applicable to deep-sea studies. Despite

numerous attempts and great success with such species as the bigfin (Lycodes

cortezianus), persimmon, midwater, and pallid eelpouts, researchers have been

unable to rear two-line eelpouts in captivity for grow-out studies (G.

VanDykhuizen, Monterey Bay Aquarium, pers. comm.; R. Vetter, National Marine

Fisheries Service, pers. comm.). Due to the time and expense involved in

capturing two-line eelpouts, cruises could not be scheduled to permit capturing

them at varying times of year to provide for marginal increment otolith analysis.

Most traditional validation techniques simply cannot be utilized in this study.

Even the most promising validation technique, radiochemistry, could not

be applied to determine the age of two-line eelpout otoliths. Campana et aL

(1989) noted that the basis for radiochemical age detenmination is the

incorporation of the caicium analog Ra-226 into the accreting crystalline

structure of the Otolith. Over time, Ra-226 decays radioactively to daughter

products. The ratio of Ra-226 to radio-isotope daughter products, usually Pb-

210, remaining in the otolith core (Pb-210 that has been decaying over the entire

life of the fish) at the time of collection can be used to effectively determine the

age of the specimen (Smith eta!. 1991 ). Extraction of these isotopes, however,

can be problematic, and their applicability in aging a short-lived fish has not

28 been proven.

Radiochemistry techniques simply lack the technology necessary for application to this study at this time. Radium detection techniques are not currently refined enough to count Ra-226 contained in an otolith directly and our attempts to do so were unsuccessfuL New techniques are being developed at

Moss Landing Marine Laboratories, however, and future application is promising. Rn-222 emanation has been used to determine the amount of Ra-

226 present in an otolith (Sarmiento et aL 1976, Kastelle at al. 1994, Klein, in press), however, it has never been used to age a short lived fish. Due to the extremely small nature of the otoliths, even in the largest specimens, whole otoliths was required to obtain enough material for Po-21 0 analysis, used to determine the amount of Pb-21 0 present The use of whole otoliths could theoretically be corrected for according to Bennett et aL ( 1982), however, this results in a huge loss in accuracy. There is promise that this technique may be improved upon by researchers at Moss Landing Marine Laboratories as welL

Attempts are still underway to refine and redevelop such techniques to validate two-line eelpout growth with the goal in mind to eventually publish this study.

Until progress is made" in our understanding of this technique, however, our best estimates of age for the two-line eelpout will have to suffice.

Reproduction and Demography

Due to the size and relatively low number of eggs present, the eggs are probably deposited in some type of nest or burrow. Kendall et. al. (1983) hypothesize that two-line eelpouts lay relatively large eggs (few in number) in shallow burrows in the sediment but this has not yet been verified. All zoarcid

29 species in the northeast Pacific, for which reproductive mode is known, are oviparous. Oviparous species have been observed guarding their eggs by wrapping themselves around the egg mass (Matarese et al 1989). The Atlantic meso pelagic zoarcid (Melanostigma atlanticum) has been found in burrows as deep as 200 mm below the sediment surface with clusters of eggs, and up to

320 mm deep the sediment without egg clusters (Silverberg et al1987). The eggs from two-line eelpouts appear to be adhesive, as is described for other demersal species, which would support their being laid in some type of cluster.

Captive studies of other eelpout species, however, would indicate that eelpout eggs may not remain on the bottom. The pallid eelpout has been kept in captivity and females have been observed reaching maturity and laying egg masses (G. VanDykhuizen, Monterey Bay Aquarium, pers. comm.). Egg~ were

3-4 em in diameter and clutches averaged 60-70 eggs per clutch. The e'ggs were adhesive when laid, however, after sitting on the bottom, the eggs separated and were very buoyant. Robison and Lancraft (1984), however, measured the buoyancy of midwater eelpout eggs and found them to be negatively buoyant when ripe. Like the two-line eelpout, larvae of the midwater eel pout are absent fro{)l extensive trawling studies of the mid water zone (upper

1500 m of the wpter column). Another related family of primarily benthic and benthopelagic fishes, Liparidae, have also been noted as having very large, negatively buoyant eggs (Stein 1980, Robison and Lancraft 1984), indicating this trait may not be uncommon to fishes of this realm.

Newly hatched larvae of all zoarcid species known are quite advanced and strongly resemble the adult specimens (Anderson 1984). Gage and Tyler

30 (1 991) speculate that larval fish of this type probably do not move far from the hatching site (which would explain the possible incidence of cannibalism discussed in the previous section).

The single, apparently gravid female (522 mm TL) was collected in

September of 1991. Many specimens containing small eggs were collected at the Columbia River mouth and Monterey Bay sites in October and November of

1992. These specimens were roughly the same size or larger than the mature specimen above. It is unknown whether the small eggs observed were reproductive material forming already for the next year. It seems unlikely that these eggs could mature rapidly enough to be spawned that same season since females collected over a two month period (October through November) were all in the exact same reproductive condition. Kliever ( 1 976) reports that persimmon eel pouts from Monterey Bay spawn in both fall and spring. Anderson (1977) found that ripe individuals of pallid eel pout also from Monterey Bay were found year round and there appeared to be no spawning "season". Similarly, the liparid family, on which much work has been conducted, contains species capable of spawning year round and others that spawn only seasonally (Stein

1980). Determining a ~pawning season is difficult for two-line eelpouts with the available information.

Some females larger than the single gravid individual observed contained no reproductive material, indicating that it is quite possible that female two-line eelpouts spawn only once their entire lives, or less frequently than annually.

Stein (1985) argues for semelparity in a deep-sea rattail species

(Coryphaenoides armatus, Family Macrouridae) based on the observation that

31 females become reproductive at very large sizes and gravid females are rarely captured. I found possible iteroparity in only one female {617 mm TL) in which approximately 18 apparently degenerating eggs were present along with small eggs, as if the female had nat spawned and had resorbed those eggs to start a new brood. Individuals containing small eggs may harbor those eggs for several years until they reach maturity. Individuals containing medium eggs are likely in a "holding pattern", waiting for appropriate conditions to invest the energy to advance to maturity and grow their eggs to full size. Such conditions may be the presence of males or adequate food supply. Speculation is difficult since the zoarcid family is one of the most diverse families regarding mode of reproduction of any of the perciform fish families (Kendall et al 1983).

lteroparity is an adaptive advantage only if survival from zygote to' maturity is uncertain (Stearns 1976, Mann and Mills 1979). Constant mortality estimates indicate semelparity may be an adaptive advantage for the two-line eelpout. Two-line eelpouts may protect their young in some form (laying eggs in a burrow), increasing the chances of survival for juveniles and countering the effect of possible cannibalism on young fish. This would also indicate that semelparity is favored'over iteroparity for best chances of reproductive success

(Mann and Mills-1979).

Semelparity may be a strategy adopted by other eel pout species as well.

Midwater eelpouts appear to have delayed reproduction until the last 1-2 years of life, and females rarely reproduce more than once. The same may possibly hold true for males (Lancraft 1982). A female pallid eelpout in captivity was observed producing a second brood, however, these have been successfully

32 kept alive for only the last 1.5-2 years, and the eggs produced by all females in

captivity were not viable (G. VanDykhuizen, Monterey Bay Aquarium, pers.

comm.) Two-line eel pouts appear to have potential for reaching maturity within

the last 5-6 years of life, or even earlier. Females with medium eggs could be

said to be in a holding pattern, waiting for appropriate conditions to advance to

maturity and begin reproducing. Craig (1985) noted, however, that semelparous

species often extend the period over which they reproduce by maturing at

different ages. Stein (1985) also observed that reproduction was not

simultaneous within the population for the possibly semelparous rattail.

Semelparity is reported for unrelated bathypelagic species and appears to be

more common with increasing body size (Childress et al. 1980).

Mortality estimates (z) were dependent on possible longevity estirtlates.

All estimates of z fell within the range of possible values for fish published by

Hoenig and Gruber (1982). The possible values range from approximately 0.15 to 0.8. Estimates of 0.20 to 0.31 seem reasonable considering the lifestyle of the two-line eelpout, however, constant mortality is unlikely. The sampling bias

indicated by the catch curve could be interpreted several ways. Larger individuals may not been sampled by this study. The presence of a few very

large individual~ would cause the curve to slope downward beyond 14 years of

age (type Ill). Younger fish were probably not sampled effectively by the trawls,

and many more probably exist in the population than were sampled. This should cause a gradually decreasing slope in earlier years (type 1). It is also likely that mortality is increased in early years since possible cannibalism was observed.

Demographic estimates of G and rare closely aligned with estimates for

33 other fish species given estimated longevity (Hoenig and Gruber 1982). Given the maximum weight of two-line eel pouts collected (1 013 g), all estimates of r may be reasonable (Hoenig and Gruber 1982). The highest values for r, indicating the population is above a stable equilibrium, however, seem unrealistic, as were the longevity values used to estimate them. Changes in mortality affected estimates of r. Considering the most realistic case, a longevity of 18 years, increasing mortality in later years (type I) had little effect on r.

Increases in z in early years (type Ill), however, caused r to be reduced to levels indicating a constant equilibrium (r = 0.0), however, only for the case of semelparity. Estimates of G and r were affected most by considerations of iteroparity or semelparity. Considering, a longevity of 18 years for the case of iteroparity, a population increase of 21 fold (R0 = 21 .8) in 12 years (G = 12.8) seems unlikely, however, the same longevity in a semelparous situation predicts a population increase of 5 fold (R0 = 5.7) in 10 years (G = 10.8). Although semelparity cannot be proven for this species with the available information, it is a possible explanation for the unusual observations that were made. If possible, year round sampling and captive rearing of this species would lend a great deal of insight to two-line eelpout reproductive ecology.

34 LITERATURE CITED:

Anderson, M.E. 1977. Systematics and natural history of Lycodaous mandibularis in California waters. MS Thesis, California State University, Hayward. 89 p.

__. 1980. Aspects of the natural history of the midwater fish Lycodapus mandibularis (Zoarcidae) in Monterey Bay, California. Pacific Science 34:181-193.

__. 1982. Revision of the fish genera Gymnelus Reinhardt and Gymneloosis Soldatov (Zoarcidae), with two new and comparative osteology of Gymnelus viridis. National Museum of Natural Science Publications in Zoology, No. 17. National Museum of Canada. 76 p.

1984. Zoarcidae: Development and Relationships. In: Ontogeny and Systematics of Fishes. American Society of Ichthyologists and Herpetologists Special Publication no. 1. pp 578-582.

Andriiashev, A.P. 1954. Fishes of the Northeastern Seas of the USSR. ,Isreal Programs for Scientific Translation, Jerusalem. 617 p.

Bayliff, W.H. 1954. A review of the Zoarcidae of the Northeast Pacific Ocean. MS Thesis, University of Washington. 189 p.

----:· 1959. Notes on the taxonomy and distribution of certain zoarcid fishes in the Northeastern Pacific. Copeia 1:78-80.

Beamish, R.J. 1979. Differences in the age of Pacific hake (Merluccius productus) using.whole otoliths and sections of otoliths. Journal of Fisheries Research Board of Canada 36:141-151.

__, and DA' Fournier. 1981. A method for comparing the precision of a set of age determinations. Canadian Journal of Fisheries and Aquatic Science 38:982-983.

Bennett, J.T., G.W. Boehler!, and K.K. Turekian. 1982. Confirmation of longevity in Sebastes diploproa (Pisces: Scorpaenidae) from Pb-210/Ra- 226 measurements in otoliths. Marine Biology 71:209-215.

35 Boehler!, G.W. 1985. Using objective criteria and multiple regression models for age determination in fishes. Fishery Bulletin 83(2): 103-116

Bone, Q., and N.B. MarshalL 1982. Biology of Fishes. Chapman and Hall, New York. 253 p.

Brusca, R.C., and G.J. Brusca. 1990. Invertebrates. Sinauer Associates, Inc., Sunderland, MASS. 922 p.

Butler, T.H. 1980. Shrimps of the Pacific Coast of Canada. Department of Fisheries and Oceans, Ottawa, Canada. 280 p.

Cailliet, G.M. 1992. Demography of the central California population of the leopard shark (Triakis semifasciata). Australian Journal of Marine and Freshwater Resources 43:183-193.

Cail!iet, G.M., and A.W. Ebeling. 1990. The vertical distribution and feeding habits of two common midwater fishes (Leuroglossus stilbius and Stenobrachius leucopsarus) off Santa Barbara. CaiCOFI Reports 31:106- 122.

Cai/liet, G.M., M.S. Love, and A.W. Ebeling. 1986. Fishes: A Field and Laboratory Manual on their Structure, Identification, and Natural History. Wadsworth Publishing Co, Belmont, CA. 194 p.

Cailliet, G.M., E.K. Osada, and M. Moser. 1988. Ecological studies of sablefish in Monterey Bay. California Fish and Game 74(3):132-153.

Campana, S.E., K.C.T. Zwanenburg, and J.N. Smith. 1989. Pb-210/Ra-226 determination of·longevity in redfish. Canadian Journal of Fisheries and Aquatic Science 47:163-165.

Childress, J.J., S.M. Taylor, G.M. Cailliet, and M.H. Price. 1980. Patterns of growth, energy utilization and reproduction in some meso- and bathypelagic fishes off southern California. Marine Biology 61 :27-40.

Chilton, D.E., and R.J. Beamish. 1982. Age determination methods for fishes studies by the Groundfish Program at the Pacific Biological Station. Special Publication Canadian Journal of Fisheries and Aquatic Science 60. 102 p.

36 Craig, J.F. 1985. Aging in fish. Canadian Journal of Zoology 63:1-8.

Delta Point, Inc. 1992. Delta Graph Professional for Windows. Delta Point, Inc., Monterey, CA.

Eschmeyer, W.N., and E.S. Herald. 1983. A field guide to Pacific Coasts fishes of North America from the Gulf of Alaska to Baja California. The Peterson Field Guide Series. Houghton Mifflin Co, Boston. 336 p.

Fitch, J.E., and R.J. Lavenberg. 1968. Deep-water Teleostean Fishes of California. University of California Press, Berkeley. 155 p.

Gage, J.D., and P.A. Tyler. 1991. Deep-Sea Biology: A Natural History of Organisms at the Deep-Sea Floor. Cambridge University Press, New York. 504 p.

Gotshall, D. W. 1971. Occurrences of the bearded eel pout Lyconema barbatum off northern California and southern Oregon. California Fish and Game 57(4):295-297.

Gotshall, D.W., and R.S. Dyer. 1987. Deepwater demersal fishes observed from the submersible Avalon (DRSV-2) off the Farallon Islands, 24 June 1985. Marine Resources Technical Report No. 55, California Fish and Game. 15 p.

Hart, J.L. 1980. Pacific Fishes of Canada. Fisheries Research Board of Canada. 740 p.

Horn, M.S., and K.S. Messer. 1992. Fish guts as chemical reactors: a model of the alimentary canals of marine herbivorous fishes. Marine Biology 113:527-535.

Hoenig, J.M., and S.H. Gruber. 1983. Life-history patterns in the elasmobranchs: Implications for fisheries management. Elasmobranchs as Living Resources. pp 1-16.

Hoenig, J.M. 1982. Empirical use of longevity data to estimate mortality rates. Fishery Bulletin 82(1 ):898-903.

Hopkins, T.L., and R.C. Baird. 1975. Net feeding in mesopelagic fishes. Fishery Bulletin 73(4):908-914.

37 Houston, K.A., and R.L Haedrich. 1986. Food habits and intestinal parasites of deep demersal fishes from the Upper Continental Slope east of Newfoundland, Northwest Atlantic Ocean. Marine Biology 92:563-574.

Hunter, J.R., J.L Butler, C. Kimbrell, and E.A. Lynn. 1990. Bathymetric patterns in size, age, sexual maturity, water content, and caloric density of Dover sole, Microstomus pacificus. CaiCOFI Reports 31:132-144.

Kastelle, C.R., O.K. Kimura, A.E. Ahmad, and D.R. Gunderson. 1994. Using Pb-21 0/Ra-226 disequilibria for sablefish, Anoplopoma fimbria, age validation. Fishery Bulletin 92(2):292-301.

Kathman, R.D., W.C. Austin, J.C. Saltman, and J.D. Fulton. Identification manual to the Mysidacea and Euphausiacea of the Northeast Pacific. Canadian Special Publication of Fisheries and Aquatic Sciences 93. 411 p.

Kappenman, R. F. 1981. A method for growth curve comparisons. Fishery Bulletin 79(1}:95-101.

Keats, D.W., D.H. Steele, and G.R. South. 1987. Ocean Pout (Macrozoarces americanus (Bloch & Schneider} (Pisces:Zoarcidae}} predation on green sea urchins (Strongylocentrotus droebachiensis (O.F. Mull) (Echinodermata:Echinoidea)) in Eastern Newfoundland. Canadian Journal of Zoology 65:1515-1521.

Kendall, A.W. Jr, C.D. Jennings, T.M. Beasley, R. Carpenter, and B.LK. Somayajulu. 1983. Discovery of a cluster of unhatched fish eggs of a zoarcid buried 10 to 12 em deep in continental slope sediments off Washington State, USA. Marine Biology 75:193-199.

Klein, D.E. in press. Radiometric age verification for two species of deep-sea rockfish (Sebastolobus altivelis and Sebaslolobus alascanus). MS Thesis, San Jose Stale University.

Kliever, R.G. 1976. Natural History of Maynea californica (Pisces: Zoarcidae) in a drift seaweed habitat in the Monterey Submarine Canyon, Monterey Bay, California. MA Thesis. San Jose State University. 70 p.

Krebs, C.J. 1989. Ecological Methodology. Harper & Row, New York. 654 p.

38 Kosloff, E. N. 1987. Marine Invertebrates of the Pacific Northwest University of Washington Pres, Seattle, WA 511 p.

Lancraft, T.M. 1982. Aspects of the natural history of Melanostigma pammelas (Pisces: Zoarcidae). MA Thesis, University of California at Santa Barbara. 137 p.

Levings, C. 1967. Aspects of the natural history of Lycodopsis pacifica (Collett) 1879. MS Thesis, University of British Columbia. 81 p.

Livingston, P.A, and B.J. Gainey Jr. 1983. Food habits literature of North Pacific marine fishes: A review and selected bibliography. NOAA Technical Memorandum NMFS F/NWC-54. US Dept. Commerce. 81 p.

Mann, R.H.K., and C.A Mills. 1979. Demographic aspects offish fecundity. In: Fish Phenology: Anabolic Adaptiveness in Teleosts, P.J. Miller (ed.). Symposium of Zoological Society of London, No. 44. pp 161-177.

Marshall, N.B. 1979. Deep Sea Biology: Developments and Perspectives. Garland STPM Press, New York. 566 p.

Matarese, AC., AW. Kendall, Jr., D.M. Blood, and B.M. Vinter. 1989. Laboratory Guide to Early Life History Stages of Northeastern Pacific Fishes. NOAA Technical Report NMFS 80. US Department of Commerce. 652 p.

Mauchline J., and J.D.M. Gordon. 1984. Occurence and feeding of berycomorphid and percomorphid teleost fish in the Rockall Trough. Journal Cons. int. Explor. Mer. 41 :239-247.

Me Allister, DE; M.E. Anderson, and J.G. Hunter. 1981. Deep water eel pouts, Zoarcidae; from Arctic Canada and Alaska. Canadian Journal of Fisheries and Aquatic Science 38:821-839.

Me Donald, J.S., KG. Waiwood, and R.H. Green. 1982. Rates of digestion of different prey in Atlantic Cod (Gadus morhua), ocean pout (Macrozoarces americanus), winter flounder (Pseudopleuronectes americanus), and American plaice (Hippoglossoides platessoides). Canadian Journal of Fisheries and Aquatic Science 39:651-659.

39 Me Donald, P.D.M., and T.J. Pitcher. Age-groups from size frequency data: A versatile and efficient method of analyzing distribution mixtures. Journal of the Fisheries Research Board of Canada 36:987-1001.

Me Kenzie, C., and J.R. Moring. 1988. Estimation of survival of Atlantic salmon during the intergravel period. North American Journal of Fisheries Management 8:45-49.

Miller, D.J., and R.N. Lea. 1972. Guide to Coastal Marine Fishes of Califonia. California Fish Bulletin No. 157. Publication 4065 of the Cooperative Extension University of California, Division of Agriculture and Natural Resources. 249 p.

Morrison, P.F., J.F. Leatherland, and R.A. Sonstegard. 1985. Comparative fecundity and egg survival of coho salmon (Oncorhynchus kisutch Walbaum) from lakes Ontario, Erie, and Michigan. Canadian Journal of Zoology 63:1096-1100.

Moyie, P.B., and J.J. Cech. 1988. Fishes, An Introduction to Ichthyology, 2nd ed. Prentice Hall, Englewood Cliffs, New Jersey. 559 p.

Nielsen, L.A., D.L. Johnson, and S.S. Lampton. 1983. Fisheries Techniques. American Fisheries Society, Bethesda, Maryland. 209 p.

Pearcy, W.G., E.E. Krygier, R. Mesecar, and F. Ramsey. 1977. Vertical distribution and migration of oceanic micro nekton off Oregon. Deep-Sea Research 24:223-245.

Pearcy, W.G., D.L. Stein, R.S. Carney. 1982. The deep-sea benthic fish fauna of the northeastern Pacific Ocean on Cascadia and Tufts Abyssal Plains and adjoining continental slopes. Biological Oceanography 1 (4):375-428.

Pereyra, W.T., and M.S. Alton. 1972. Distribution and relative abundance of invertebrates off the northern Oregon coast. In: The Columbia River Estruary Adjacent Ocean Waters: Bioenvironmental Studies, AT. Pruter and D.L. Alverson (eds.). University of Washington Press, Seattle, WA. pp 444-474.

Pinkas, L., M.S. Oliphant, and I.L.K. Iverson. 1971. Food habits of albacore, bluefin tuina, and bonito in California waters. California Department Fish and Game, Fish Bulletin No. 152. 105 p.

40 Ricker, W.E. 1975. Computation and interpretation of biologcal statistics of fish populations. Journal of the Fisheries Research Board of Canada, Bulletin No. 191. 120 p.

Robison, B.H., and T.M. Lancraft. 1984. An upward transport mechanism from the benthos. Naturwissenschaften 71:322-324.

SAl C. 1992. Detailed physical and biological oceanographic studies for an ocean site designation effort under Marine Protection, Research and Sanctuaries Act of 1972 (MPRSA). Final Trawl and Remotely Operated Vehicle (ROV) Ocean Studies Report submitted to U.S. Environmental Protection Agency under EPA Contract No. 68-C8-0062.

Saila, S.B., C.W. Recksiek, and M H. Prager. 1988. Basic Fishery Science Programs; A Compendium of Microcomputer Programs and Manual of Operation. Developments in Aquaculture and Fisheries Science (18), Elsevier, New York. 230 p.

Sarmiento, J.L., D.E. Hammond, and W.S. Broecker. 1976. The calcula.tion of the statistical counting error for Rn-222 scintillation counting. Earth and Planetary Sciences Letters 32:351-356.

Schmidt, W.L. 1921. The' Marine Decapod Crustacea of California. University of California Press, Berkeley, CA. 470 p.

Scrivener, J.C. 1988. Two devices to assess incubation survival and emergence of salmonid fry in an estuary streambed. North American Journal of Fisheries Management 8:248-258.

Silver, M.W. 1975. The habitat of Salpa fusiformis in the California Current as defined by· indicator assemblages. Limnology and Oceanography 20(2):230~237.

Silverberg, N., H.M. Edenborn, G. Ouellet, and P. Beland. 1987. Direct evidence of a mesopelagic fish, Melanostigma atlanticum (Zoarcidae), spawning within bottom sediments. Environmental Biology of Fishes 20(3): 195-202.

41 Smith, C.R 1985. Food for the deep sea: utilization, dispersal, and flux of nekton falls at the Santa Catalina Basin floor. Deep-Sea Research 32(4):417-442.

Smith, J. N., R Nelson, and S.E. Campana. 1991. The use of Pb-21 0/Ra-226 and Th-228/Ra-228 disequilibria in the ageing of otoliths of marine fish. In: Radionuclides in the study of marine processes, P.J. Kershaw and D.S. Woodhead (eds.). Elsevier Applied Science, New York. pp 350-359.

Stearns, S.C. 1976. Life-history tactics: a review of ideas. Quarterly Review of Biology 51:3-47.

Stein, D.L. 1980. Aspects of reproduction of liparid fishes from the continental slope and abyssal plain off Oregon, with notes on growth. Copeia 4:687- 699.

Stein, D.L. 1985. Towing large nets by single warp at abyssal depths: methods and biological results. Deep-Sea Research 32(2):183-200.

Watters, D. L. 1993. Age determination and confirmation from otoliths of the bank rockfish, Sebastes rufus (Scorpaeidae). MS Thesis, San Jos:e State University. 33 p.

Wakefield, W.W. 1990. Patterns in the distribution of demersal fishes on the upper continental slope off central California with studies on the role of ontogenic vertical migration in particle flux. PhD dissertation, University of California, San Diego. 281 p.

Wilkinson, L., M.A. Hill, P. Howe, and S. Miceli. 1992. Systat for Windows, Version 5 Edition. Systat, Inc., Evanston, Illinois \ Zar, J.H. 1984. Biostatistical Analysis. Prentice Hall, Englewood Cliffs, New Jersey. 718 p.

42 Table 1. Summary of trawl effort by depth with catch results at all sites combined. depth no. trawls no. trawls with no. two-line two-line eel pout eelpout captured 0-99 m 0 0 0 100-199 m 7 0 0 200-299 m 19 0 0 300-399 m 25 1 0 400-499 m 28 1 1 500-599 m 17 6 31 600-699 m 16 13 75 700-799 m 28 20 117 800-899 m 18 15 202 900-999 m 18 17 120 1000-1099 m 21 17 193 1100-1199 m 16 15 169 1200-1299 m 18 14' 166 1300-1399 m 12 11 96 1400-1499 m 2 1 3 1500-1599 m 0 0 0 1600-1699 m 1 1 3 1700-1799 m 0 0 0 1800-1899 m 1 0 0 1900-1999 m 1 0 0

43 Table 2. Prey items found in the stomachs of eelpouts from the central California site and the Columbia River mouth site. Ll denotes identifications used in the descriptive IRI for general diet comparisons, and X denotes items used for specific identifications. item central California Columbia River mouth Phylum Vertebrata Pisces/Fish Remains (u) Ll Zoarcidae X Phylum Arthropoda Crustacea (u) Decapoda Caridea Heptacarpus sp. X X Mysidea (u) X X Holmsiella sp. X X Gnathophausia sp. X Eucopia sp. X Phylum Mollusca Cephalopoda X

44 Table 3. Potential prey determined from megafauna surveys of the central California site (Wakefield 1990, SAIC 1992) and the Columbia River mouth site (Pearcy et al. 1977, Pereyra and Alton 1972, Pearcy et aL 1982). Potential prey were targeted by relative abundance and size relative to the open mouth of a two-line eelpout. Question marks denote uncertain identification as indicated by the original studies. central California Columbia River mouth Ph. Vertebrata Ph. Vertebrata Stenobrachius sp. • Lampanyctus regalis* Cyclothone sp. • Bathylagus sp. • Merluccius productus Ouv.) Merluccius productus Ouv.) Bothrocara brunneum Ouv.) Bothrocara brunneum Ouv.) Lycenchelys sp. Lycenchelys sp. Lycodapus sp. Lycodapus sp. Sebastolobus sp. Uuv.) Sebastolobus sp. Sebastes sp. Uuv.) Sebastes sp. Quv.) lcelinus filamentosus Bathyagonus nigripinnis Bathyagonus nigripinnis Rhinoliparis sp. Quv.) Careproctus melanurus Uuv.) Paraliparis sp. Uuv.) Microstomus pacificus Quv.) Microstomus pacificus Ouv.) Atheresthes stomias Quv.) Embassichthys bathybius Ouv.) Embassichthys bathybius Uuv.) Errex ( = Glyptocephalus) zachirus Errex ( = Glyptocephalusl zachirus Lyopsetta exilis Lyopsetta exilis Ph. Cnidaria Anthozoa Paractinostola? Actinostola ? Lyponema? Ph. Annelida Polychaeta Aphrodita sp. Ph. Arthropoda Ph. Arthropoda Crustacea Crustacea Decapoda Decapoda Caridea Caridea Bentheogennema burkenroadi*

45 Bentheogennema borealis* Acanthephyra curtirostris* Systellaspis braueri* Pandalus platyceras Eualus micropthalma unknown caridean Mysidea Mysidea Gnathophausia ~· Ph. Mollusca Ph. Mollusca Gastropoda Gastropoda Tritonia sp. Tritonia diomedea Bathybemix biardii Ba!hybemix biardii Neptunea amianta Neptunea amian!a Buccinum strigillatum Bivalvia unknown scallop Cephalopoda Cephalopoda Octopus rubescens Chiroteuthis calyx* Benthoctopus ? Japetella heathi* Opisthoteuthis californians Opisthoteu!his californiana Moroteuthis robusta Vampyroteuthis infernalis Ph. Echinodermata Ph. Echinodermata Asteroidea Asteroidea Ophiuroidea Ophiuroidea Asteronyx loveni Ophiophthalmus norman! Ophiomusium jolliensis Gorgonocephalus sp. unknown sp. Holothuroidea Holothuroidea Pannychia sp. Pannychia moseleyi Scotoplanes theeli Zygothurea lactea Echinoidea Tromikosoma-like Allocentrotus fragilis

*primarily benthopelagic prey (from Pearcy et aL 1977)

46 Table 4. Life table for two-line eelpouts for three variations in longevity and resulting instantaneous mortality (z): a} 14 years, z = .3161; b) 18 years, z = .2470; and c) 22 years, z = .2028 used to make best possible demographic estimates of generation time (G}, net reproductive rate (Ro), intrinsic rate of increase (r), and finite rate of population increase (e"r} for semelparous (S) and iteroparous (I} re reduction. A. z= .3161 n ageint. X me9n TL ( mm) growth lx %matS mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1.000 0 0.00 0.00 0.00 0.00 3 1 to 2 1 140 0.729 0 0.00 0.00 0.00 0.00 18 2 to 3 2 1762 36.2 0.531 0 0.00 0.00 0.00 0.00 12 3 to 4 3 194.6 18.4 0.387 0 0.00 0.00 0.00 0.00 13 4 to 5 4 239.4 44.8 0.282 0 0.00 0.00 0.00 0.00 13 5 to 6 5 271.2 31.8 0.206 0 0.00 0.00 0.00 0.00 22 6 to 7 6 310.8 39.6 0.150 0 0.00 0.00 0.00 0.00 23 7 to 8 7 362.3 51.5 0.109 0 0.00 0.00 0.00 0.00 .!>, "-J 37 8 to 9 8 407.5 45.2 0.080 0 0.00 0.00 0.00 0.00 22 9 to 10 9 454.5 47 0.058 0.2 99.88 19.98 1.16 10.45 27 10 to 11 10 498.1 43.6 0.042 0.15 99.88 14.98 0.63 6.35 19 11 to 12 11 522.2 24.1 0.031 0.1 99.88 9.99 0.31 3.39 9 12 to 13 12 543.7 21.5 0.023 0.1 99.88 9.99 0.22 2.70 11 13 to 14 13 567.5 23.8 0.016 0.1 99.88 9.99 0.16 2.13 3 14+ 14 586.3 18.8 0.012 0.05 99.88 4.99 0.06 0.84 avg. growth= 34.3308 Ro= 2.55 25.86 G= 10.13 r= 0.09

e"r= 1.10 Table 4A continued n ageint. X mean TL (mm) growth lx %mat I mx mx' lx*mx' x*lx*mx' 0 o to 1 0 na 1.000 0 0.00 0.00 0.00 0.00 3 1 to 2 1 140 0.729 0 0.00 0.00 0.00 0.00 18 2 to 3 2 176.2 36.2 0.531 0 0.00 0.00 0.00 0.00 12 3 to 4 3 194.6 18.4 0.387 0 0.00 0.00 0.00 0.00 13 4 to 5 4 239.4 44.8 0.282 0 0.00 0.00 0.00 0.00 13 5 to 6 5 271.2 31.8 0.206 0 0.00 0.00 0.00 0.00 22 6 to 7 6 310.8 39.6 0.150 0 0.00 0.00 0.00 0.00 23 7 to 8 7 362.3 51.5 0.109 0 0.00 0.00 0.00 0.00 37 8 to 9 8 407.5 45.2 0.080 0 0.00 0.00 0.00 0.00 22 9 to 10 9 454.5 47 0.058 0.2 99.88 19.98 1.16 10.45 27 10 to 11 10 498.1 43.6 0.042 0.35 99.88 34.96 1.48 14.82 19 11 to 12 11 522.2 24.1 0.031 0.45 99.88 44.94 1.39 15.28 9 12 to 13 12 543.7 21.5 0.023 0.55 99.88 54.93 1.24 14.85 .I:> co 11 13 to 14 13 567.5 23.8 0.016 0.65 99.88 64.92 1.07 13.86 3 14+ 14 586.3 18.8 0.012 0.7 99.88 69.91 0.84 11.72 Ro= 7.17 80.96 G= 11.29 r= 0.17

eAr= 1 '19 B. z = .2470 n age in!. X mean TL (mm) growth lx %matS mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1.000 0 0.00 0.00 0.00 0.00 3 1 to 2 1 140 0.781 0 0.00 0.00 0.00 0.00 18 2 to 3 2 176.2 36.2 0.610 0 0.00 0.00 0.00 0.00 12 3 to 4 3 194.6 18.4 0.477 0 0.00 0.00 0.00 0.00 13 4 to 5 4 239.4 44.8 0.372 0 0.00 0.00 0.00 0.00 13 5 to 6 5 271.2 31.8 0.291 0 0.00 0.00 0.00 0.00 22 6 to 7 6 310.8 39.6 0.227 0 0.00 0.00 0.00 0.00 23 7 to 8 7 362.3 51.5 0.177 0 0.00 0.00 0.00 0.00 37 8 to 9 8 407.5 45.2 0.139 0 0.00 0.00 0.00 0.00 22 9 to 10 9 454.5 47.0 0.108 0.2 99.88 19.98 2.16 19.47 27 10 to 11 10 498.1 43.6 0.085 0.15 99.88 14.98 1.27 12.67 19 11 to 12 11 522.2 24.1 0.066 0.1 99.88 9.99 0.66 7.26 9 12 to 13 12 543.7 21.5 0.052 0.1 99.88 9.99 0.52 6.19 .!>.

eAr= 1.17 Table 48 continued n a9eint. X mean TL (mm) growth lx %mat I mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1.000 0 0.00 0.00 0.00 0.00 3 1 to 2 1 140 0.781 0 0.00 0.00 0.00 0.00 18 2to 3 2 176.2 36.2 0.610 0 0.00 0.00 0.00 0.00 12 3 to 4 3 194.6 184 0.477 0 0.00 0.00 0.00 0.00 13 4to 5 4 ?39.4 44.8 0.372 0 0.00 0.00 0.00 0.00 13 5 to 6 5 271.2 31.8 0.291 0 0.00 0.00 0.00 0.00 22 6 to 7 6 310.8 39.6 0.227 0 0.00 0.00 0.00 0.00 23 7 to 8 7 362.3 51.5 0.177 0 0.00 0.00 0.00 0.00 37 8 to 9 8 407.5 45.2 0.139 0 0.00 0.00 0.00 0.00 22 9 to 10 9 454.5 47.0 0.108 0.2 99.88 19.98 2.16 19.47 27 10 to 11 10 498.1 43.6 0.085 0.35 99.88 34.96 2.96 29.57 19 11 to 12 11 522.2 24.1 0.066 0.45 99.88 44.94 2.97 32.67 9 12 to 13 12 543.7 21.5 0.052 0.55 99.88 54.93 2.84 34.02 01 a 11 13 to 14 13 567.5 23.8 0.040 0.65 99.88 64.92 2.62 34.03 3 14 to 15 14 586.3 18.8 0.031 0.7 99.88 69.91 2.20 30.83 0 15 to 16 15 620.6 34.3 0.025 0.75 99.88 74.91 1.84 27.64 0 16 to 17 16 654.9 34.3 0.019 0.85 99.88 84.90 1.63 26.10 0 17 to 18 17 689.2 34.3 0.015 0.95 99.88 94.88 1.42 24.21 0 18 to 19 18 723.5 34.3 0.012 1 99.88 99.88 1.17 21.08 Ro= 21 81 279.61 G= 12.82 r= 0.24

eAr= 1.27 C. z = .2028 n age in!. X mean TL (mm) growth lx %matS mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1.000 0 0.00 0.00 0.00 0.00 3 1 to 2 1 140 0.816 0 0.00 0.00 0.00 0.00 18 2 to 3 2 176.2 36.2 0.667 0 0.00 0.00 0.00 0.00 12 3 to 4 3 194.6 18.4 0.544 0 0.00 0.00 0.00 0.00 13 4 to 5 4 . 239.4 44.8 0.444 0 0.00 0.00 0.00 0.00 13 5 to 6 5 271.2 31.8 0.363 0 0.00 0.00 0.00 0.00 22 6 to 7 6 310.8 39.6 0.296 0 0.00 0.00 0.00 0.00 23 7 to 8 7 362.3 51.5 0.242 0 0.00 0.00 0.00 0.00 37 8 to 9 8 407.5 45.2 0.197 0 0.00 0.00 0.00 0.00 22 9 to 10 9 454.5 47.0 0.161 0.2 99.88 19.98 3.22 28.98 27 10 to 11 10 498.1 43.6 0.132 0.15 99.88 14.98 1.97 19.72 19 11 to 12 11 522.2 24.1 0.107 0.1 99.88 9.99 1.07 11.80 9 12 to 13 12 543.7 21.5 0.088 0.1 99.88 9.99 0.88 10.51 U1 ~ 11 13 to 14 13 567.5 23.8 0.072 0.1 99.88 9.99 0.72 9.30 3 14 to 15 14 586.3 18.8 0.058 0.05 99.88 4.99 0.29 4.09 0 15 to 16 15 620.6 34.3 0.048 0.05 99.88 4.99 0.24 3.58 0 16 to 17 16 654.9 34.3 0.039 0.05 99.88 4.99 0.19 3.11 0 17 to 18 17 689.2 34.3 0.032 0.05 99.88 4.99 0.16 2.70 0 18 to 19 18 723.5 34.3 0.026 0.05 99.88 4.99 0.13 2.34 0 19 to 20 19 757.8 34.3 0.021 0.025 99.88 2.50 0.05 1.01 0 20 to 21 20 792.1 34.3 0.017 0.025 99.88 2.50 0.04 0.86 0 21 to 22 21 826.4 34.3 0.014 0.025 99.88 2.50 0.04 0.74 0 22 to 23 22 860.7 34.3 0.012 0.025 99.88 2.50 0.03 0.63 Ro= 9.03 99.37 G= 11.00 r= 0.20 eAr= 1.22 Table 4C continued n age int. X mean TL (mm) growth lx %mat I mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1.000 0 0.00 0.00 0.00 0.00 3 1 to 2 1 140 0.816 0 0.00 0.00 0.00 0.00 18 2 to 3 2 176.2 36.2 0.667 0 0.00 0.00 0.00 0.00 12 3 to 4 3 194.6 18.4 0.544 0 0.00 0.00 0.00 0.00 13 4 to 5 4 239.4 44.8 0.444 0 0.00 0.00 0.00 0.00 13 5 to 6 5 271.2 31.8 0.363 0 0.00 0.00 0.00 0.00

22 6 to 7 6 310.8. 39.6 0.296 0 0.00 0.00 0.00 0.00 23 7 to 8 7 362."3 51.5 0.242 0 0.00 0.00 0.00 0.00 37 8 to 9 8 407.5 45.2 0.197 0 0.00 0.00 0.00 0.00 22 9 to 10 9 454.5 47.0 0.161 0.2 99.88 19.98 3.22 28.98 27 1 0 to 11 10 498.1 43.6 0.132 0.35 99.88 34.96 4.60 46.00 19 11 to 12 11 522.2 24.1 0.107 0.45 99.88 44.94 4.83 53.12 9 12 to 13 12 543.7 21.5 0.088 0.55 99.88 54.93 4.82 57.82 U1 N 11 13 to 14 13 567.5 23.8 0.072 0.65 99.88 64.92 4.65 60.44 3 14 to 15 14 586.3 18.8 0.058 0.7 99.88 69.91 4.09 57.23 0 15 to 16 15 620.6 34.3 0.048 0.75 99.88 74.91 3.58 53.64 0 16 to 17 16 654.9 34.3 0.039 0.8 99.88 79.90 3.11 49.83 0 17 to 18 17 689.2 34.3 0.032 0.85 99.88 84.90 2.70 45.93 0 18 to 19 18 723.5 34.3 0.026 0.9 99.88 89.89 2.34 42.04 0 19 to 20 19 757.8 34.3 0.021 0.925 99.88 92.39 1.96 37.23 0 20 to 21 20 792.1 34.3 0.017 0.95 99.88 94.88 1.64 32.86 0 21 to 22 21 826.4 34.3 0.014 0.975 99.88 97.38 1.38 28.91 0 22 to 23 22 860.7 34.3 0.012 1 99.88 99.88 1.15 25.37 Ro= 44.07 619.41 G= 14.06 r= 0.27 e~r= 1.31 Table 5. Life table for two-line eelpouts with a longevity of 18 years and changes in instantaneous mortality such that: a} mortality is increased in early years resembling a type Ill mortality; and b} mortality is increased in later years resembling a type I mortality, resulting in reduced estimates of generation time (G), net reproductive rate (Ro}, intrinsic rate of increase (r}, and finite rate of population increase (eAr} for semelparous (S) and iterO[!arous II) reeroduction. A type Ill mortality n ageint. X mean TL (mm) growth z lx %matS mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1 0.00 0.00 0.00 0.00 0 3 1 to 2 1 140.· 0.741 0.4766 0.00 0.00 0.00 0.00 0 18 2 to 3 2 176.2 36.2 0.494 0.2908 0.00 0.00 0.00 0.00 0 12 3 to 4 3 194.6 18.4 0.247 0.2272 0.00 0.00 0.00 0.00 0 13 4 to 5 4 239.4 44.8 0.247 0.1775 0.00 0.00 0.00 0.00 0 13 5 to 6 5 271.2 31.8 0.247 0.1386 0.00 0.00 0.00 0.00 0 22 6 to 7 6 310.8 39.6 0.247 0.1083 0.00 0.00 0.00 0.00 0 23 7 to 8 7 362.3 51.5 0.247 0.0846 0.00 0.00 0.00 0.00 0 (JJ w 37 8 to 9 8 407.5 45.2 0.247 0.0661 0.00 0.00 0.00 0.00 0 22 9 to 10 9 454.5 47 0.247 0.0516 0.20 99.88 19.98 1.03 9.27879 27 10 to 11 10 498.1 43.6 0.247 0.0403 0.15 99.88 14.98 0.60 6.040033 19 11 to 12 11 522.2 24.1 0.247 0.0315 0.10 99.88 9.99 0.31 3.459952 9 12 to 13 12 543.7 21.5 0.247 0.0246 0.10 99.88 9.99 0.25 2.94841 11 13 to 14 13 567.5 23.8 0.247 0.0192 0.10 99.88 9.99 0.19 2.49505 3 14 to 15 14 586.3 18.8 0.247 0.015 0.05 99.88 4.99 0.07 1.049453 0 15 to 16 15 620.6 34.3 0.247 0.0117 0.05 99.88 4.99 0.06 0.878326 0 16 to 17 16 654.9 34.3 0.124 0.0104 0.10 99.88 9.99 0.10 1.656071 0 17 to 18 17 689.2 34.3 0.082 0.0095 0.10 99.88 9.99 0.10 1.620507 0 18 to 19 18 723.5 34.3 0.082 0.0088 0.05 99.88 4.99 0.04 0.79011 Ro= 2.76 30.2167 G= 10.93 r= 0.09 eAr= 1.10 Table SA continued n ageint. X mean TL {mm) growth lx %matt mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1 0.00 0.00 0.00 0.00 0 3 1 to 2 1 140 0.741 0.4766 0.00 0.00 0.00 0.00 0 18 2 to 3 2 176.2 36.2 0.494 0.2908 0.00 0.00 0.00 0.00 0 12 3 to 4 3 194.6 18.4 0.247 0.2272 0.00 0.00 0.00 0.00 0 13 4 to 5 4 239.4 44.8 0.247 0.1775 0.00 0.00 0.00 000 0 13 5 to 6 5 271.2 31.8 0.247 0.1386 0.00 0.00 0.00 0.00 0 22 6 to 7 6 310.1,3 39.6 0.247 0.1083 0.00 0.00 0.00 0.00 0 23 7 to 8 7 362.3 51.5 0.247 0.0846 0.00 0.00 0.00 0.00 0 37 8 to 9 8 407.5 45.2 0.247 0.0661 0.00 0.00 0.00 0.00 0 22 9 to 10 9 454.5 47 0.247 0.0516 0.20 99.88 19.98 1.03 9.27879 27 10 to 11 10 498.1 43.6 0.247 0.0403 0.35 99.88 34.96 1.41 14.09341 19 11 to 12 11 522.2 24.1 0.247 0.0315 0.45 99.88 44.94 1.42 15.56978 9 12 to 13 12 543.7 21.5 0.247 0.0246 0.55 99.88 54.93 1.35 16.21625 (J1 ~ 11 13 to 14 13 567.5 23.8 0.247 0.0192 0.65 99.88 64.92 125 16.21782 3 14 to 15 14 586.3 18.8 0.247 0.015 0.70 99.88 69.91 1.05 14.69235 0 15 to 16 15 620.6 34.3 0.247 0.0117 0.75 99.88 74.91 0.88 13.17489 0 16 to 17 16 654.9 34.3 0.124 0.0104 0.85 99.88 84.90 0.88 14.07661 0 17 to 18 17 689.2 34.3 0.082 0.0095 0.95 99.88 94.88 0.91 15.39482 0 18 to 19 18 723.5 34.3 0.082 0.0088 1.00 99.88 99.88 0.88 15.80221 Ro= 11.05 144.5169 G= 13.08 r:: 0.18

eAr= 1.20 B. type l mortality n a£leint X mean TL (mm) £lfOwth z lx %matS mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1 0.00 0.00 0.00 0.00 0 3 1 to 2 1 140 0.247 0.7811 0.00 0.00 0.00 0.00 0 18 2 to 3 2 176.2 36.2 0.247 0.6102 0.00 0.00 0.00 0.00 0 12 3 to 4 3 194.6 18.4 0.247 0.4766 0.00 0.00 0.00 0.00 0 13 4 to 5 4 239.4 44.8 0.247 0.3723 0.00 0.00 0.00 0.00 0 13 5 to 6 5 271.2 31.8 0.247 0.2908 0.00 0.00 0.00 0.00 0 0.00 0.00 22 6 to 7 6 310.8,• 39.6 0.247 0.2272 0.00 0.00 0 23 7 to 8 7 362.3 51.5 0.247 0.1775 0.00 0.00 0.00 0.00 0 37 8 to 9 8 407.5 45.2 0.247 0.1386 0.00 0.00 0.00 0.00 0 22 9 to 10 9 454.5 47 0.247 0.1083 0.20 99.88 19.98 2.16 19.4672 27 10 to 11 10 498.1 43.6 0.247 0.0846 0.15 99.88 14.98 1.27 12.67219 19 11 to 12 11 522.2 24.1 0.247 0.0661 0.10 99.88 9.99 0.66 7.259091 9 12 to 13 12 543.7 21.5 0.247 0.0516 0.10 99.88 9.99 0.52 6.18586 U1 U1 11 13 to 14 13 567.5 23.8 0.247 0.0403 0.10 99.88 9.99 0.40 5.234696 3 14 to 15 14 586.3 18.8 0.247 0.0315 0.05 99.88 4.99 0.16 2.201787 0 15 to 16 15 620.6 34.3 0.247 0.0246 0.05 99.88 4.99 0.12 1.842756 0 16 to 17 16 654.9 34.3 0.494 0.015 0.10 99.88 9.99 0.15 2.398751 0 17 to 18 17 689.2 34.3 0.741 0.0072 0.10 99.88 9.99 0.07 1.214792 0 18 to 19 18 723.5 34.3 0.988 0.0027 0.05 99.88 4.99 0.01 0.239449 Ro= 5.52 58.71657 G= 10.63 r= 0.16

e~r= 1.17 Table 58 continued n ageint. X mean TL (mm) 9rowth lx %mat I mx mx' lx*mx' x*lx*mx' 0 0 to 1 0 na 1 0.00 0.00 0.00 0.00 0 3 1 to 2 1 140 0.247 0.7811 0.00 0.00 0.00 0.00 0 18 2 to 3 2 176.2 36.2 0.247 0.6102 0.00 0.00 0.00 0.00 0 12 3to 4 3 194.6 18.4 0.247 0.4766 0.00 0.00 0.00 0.00 0 13 4 to 5 4 239.4 44.8 0.247 0.3723 0.00 0.00 0.00 0.00 0 13 5 to 6 5 271.2 31.8 0.247 0.2908 0.00 0.00 0.00 0.00 0 22 6 to 7 6 310.8 39.6 0.247 0.2272 0.00 0.00 0.00 0.00 0 23 7 to 8 7 362.3 51.5 0.247 0.1775 0.00 0.00 0.00 0.00 0 37 8 to 9 8 407.5 45.2 0.247 0.1386 0.00 0.00 0.00 0.00 0 22 9 to 10 9 454.5 47 0.247 0.1083 0.20 99.88 19.98 2.16 19.4672 27 10 to 11 10 498.1 43.6 0.247 0.0846 0.35 99.88 34.96 2.96 29.56843 19 11 to 12 11 522.2 24.1 0.247 0.0661 0.45 99.88 44.94 2.97 32.66591 9 12 to 13 12 543.7 21.5 0.247 0.0516 0.55 99.88 54.93 2.84 34.02223 01 O'l 11 13 to 14 13 567.5 23.8 0.247 0.0403 0.65 99.88 64.92 2.62 34.02552 3 14 to 15 14 586.3 18.8 0.247 0.0315 0.70 99.88 69.91 2.20 30.82502 0 15 to 16 15 620.6 34.3 0.247 0.0246 0.75 99.88 74.91 1.84 27.64134 0 16 to 17 16 654.9 34.3 0.494 0.015 0.85 99.88 84.90 1.27 20.38938 0 17 to 18 17 689.2 34.3 0.741 0.0072 0.95 99.88 94.88 0.68 11.54052 0 18 to 19 18 723.5 34.3 0.988 0.0027 1.00 99.88 99.88 0.27 4.788974 Ro= 19.81 244.9345 G= 12.37 r= 0.24 Washington

olumbia River

Oregon

PACIFIC OCEAN California

Farallon Islands

36° N Monterey Bay 124° w

Figure 1. Map of the eastern North Pacific where two-line eelpouts were captured for study. Thatched areas indicate where trawls were conducted.

57 ~ I 0 -~I 21 lc: 0. ,._g '-> ..c:: I~ c, c: d~0 .!!! ..c:: I""' ~ .9 I 0 I I "iii !Jl !Jl ~ 0 -a 113 L/IP!M L/1!/0JO ::l I"'

ro 0 E ro ~ . OJ"' --cro­ Q

58 ~ 609-009 Q) £ 68~·08~ "0c:: 1- rn 69~·09~ ·c:<0 67~-0t:'~ .... ~ 6Z~·oz~ ·09t:' .<:: 67t>·Ot>t:' -. "0 ezv-Oc7 :::l 60v-oov "E -"'.... E 0 688-088 ~ "0 .r;; -e:: 698-098 0, :::l c: .c. (!) - 678-0t:-8 ...J B ro .<:: 6(;8·0(;8 ~ ;;::"' 608-008 .r;; rn -~ .... 0 68Z-08Z u. £ -E-'- 69(;·09(; (llC\J g Oll.(l~""'" :2 Ctl 6t>C:·OvC: .9 It ~ II) (!) c: ·- c:: > ~ .<:: ~ ,9. \ 6c:z-oc:z >.II) a: (,) OJ a:l C."t:: Ctl () 6oz-ooz (!)(}) :0 :::l.c: a:l ' c:r- E ~ :::l 68 ~ ·08 ~ W:::l ~'c: .!:;0 0 (!) () (,) 69l-09l .c::2 -Olru.... c> 1- 6t?l-Ql>l W·- ·. ...JO: L5ill. 6C:L-OC: l ,

59 1800

1600 e e II

1400- II Ill "'' 1111 .. II II» 11,: , p e , ..II w.r II 1200- OJ ~ ::J Til- 1000 u

~ 0 • 11!1 _c: BOO 0.. (J) - OJ 0 D 600 1111.4. •• 400 111 females 11 males 200 ..t. no sex determined

0 0 100 200 300 400 500 600 700 Fish Total Length

Figure 4. Distribution of male, female, and sex not determined fish captured at each depth. :;-::;-, )> 0 -· OJ No. of fish No. of fish II 3 'g 0 1\) w ..,.. U1 ()) 0 ~ 1\) w ..,.. U1 m :::j ~ ro - I I I I I I " " w ~ U1 80-89 - ~. ::r~. m r 100-109 - n m 120-129 ID :'I :J -· - -· U> 01 260-269 n;o u;· 280-289 - ~(Q :J' :J ~ : Ill -i 300-309 II 3 ~ 320-329 U1 -· ...... m U1 0 - ~ ~ 340-349 ~ Ill IU :J 360-369 ::1 a =-·Ul ~ 380-389 c;r::r - ::c: ;:: 400-409 - ::r"' 3 420-429 ID Cll o': ~ 440-449 - 0 0 460-469 - c~ 3 c: 480-489 rr ~ 500-509 -- n - w· 0 JJ :J 520-529 <'' (i) 540-549 - (1) :J ---- ~ ~ :;:3 560-569 0 Ill 580-589 c: - ::rw-'< 600-609 !!!. Ui' 620-629 = ro 10 9- 8- 7- "'X 2l 6- --- Q)""' 5- J:-""" ~ 0. 4- - zd .. 3 j. 2- ..- .I 1-. 0 ' ' ' I I 0 20' 40 60 80 100 120' 140' A. 160 180

10 9 8 •.:r--- 7 -I .- "'X 2l 6 -· Q) 5 Ci""' .-f---- 4 zd 3 J-: • 2 .••

0 I I I B. 0 20 40 60 80 100 120 140 160' 180 No. guts analyzed

Figure 6. The asymptotic nature of cumulative prey curves indicate that a sufficient number of guts were analyzed from: a) the central California site; and b) the Columbia River mouth site. Bars represent 95% confidence intervals, which tighten about the curves indicating the diets from each region were accurately characterized.

62 80 70 Fish 60 ~ Q) .0 so E z~ 40

>!<0 30 20 10 0 10 20 30 E"' 40 ~ 0 > 50 ?f. 60 70 80 A. 10 20 30 50 60 70 so 70 Fish 60 Crustaceans

-'00ID -a E :HO z ~30 0 20 10

Q 10 20 30 "'E4o ~ a so > ~60 70 80 . ---r-1 I I I I I "/co Frequency o fOccurrence B 10 20 30 40 50 60 70 Figure 7. Index of relative importance (IRI) diagram showing the similarity between diets at: a) the central California site; and b) the Columbia River mouth site, at a general level of prey item identification.

63 Holmsiella Heot acarpus

10 - 0 th er myslds '- 0.) B - I D E 6 I ::J z 4 - I 0~ 2 - 0 2 0.) - E ::J 4 - 0 > 6 r!. 8 J 10 -.-,r-~o--r-.-, A. 2 4 6 s 12 14 16 - 14 - 12 ' '- - 0.) D 10 other mysids Holmsiella E - Gnathoohausia? z::J 8 - Gnathoohausia of?. 6 - Eucopia Hept acarpus 4 - I 2 - j 0 ~i=l - ,.-J 2 - 4 -

0.) 6 - E ::J 8 - ' 0 > 10 - ' 0~ 12 - 14 - 16 - I I I I I I I oYo Frequency of Occurrence B. 2 4 6 8 10 12 14 Figure 8. Index of relative importance (IRI) diagram showing the reduced similarity in diets at: a) the central California site; and b) the Columbia River mouth site at a more specific level of prey item identification, and the slightly greater diversity in diet at the Columbia River mouth site.

64 two-line eelpout mouth:

villiform teeth

esophagus E \ E ' co L() c\J gill arches L()

557-593 mm TL 47-53 mm

prey lengths:

l------1 22-38 mm Heotacarpus

!------! 25-38 mm Holmsiella

f------!22-40 mm Eucopia

/ / to 160 mm Gnathoohausia

80-90 mm juvenile zoarcids Figure 9. Dentition patterns of two-line eelpouts for a representative sample of fish measured (n = 3). A range of gape and cleft sizes are shown along side the frontal view of the open mouth. The maximum reported lengths for prey species found in the guts is given below. 65 CARDIAC STOMACH

INTESTINE

Ol Ol

11% 95%

% of fish total length

Figure 10. Relative cardiac stomach and intestine .size of a representative sample (n = 3) of two-line eelpouts. The bar below indicates percent of fish total length that each organ represents. 14

females 12 •~ males 10 no sex determined

.r:: • 8 ~ 0 z0 6

4 - m --.J 2 -

0 u il II II I I I I llll m m m m m m m m m m m m m m m m m m m m m m m m m m ' m ' ' m co 0 N <0 co 0 N <0 co 0 N <0 co 0 N <0 co 0 N <0 co 0 N 0 ' ""'"~ N N N""'" N N C') C') C')""'" C') C') '

f(x) = .003x + .347 R2 = .878 I I I B. 0 100 200 300 400 500 600 700

0.1 ,..------...,., 2 14 f(x) = .00000008(x · ) 2 § 0.075 R = .709 .c • Cl ~ 0.05 § 0 5 0.025 •• ol-~~.---,.------r----.---1 _J 0 100 200 300 400 500 600 700 c Fish Total Length (mm) Figure 12. Plots of: a) otolith length (n = 81); and b) otolith width (n =50) versus fish total length showing the nearly linear relationship; and c) otolith weight (n = 411) versus fish total length showing the best possible fit, an exponential curve. Equations for each line are shown.

68 700~r------,------, age estimates sex 0 unknown

600 ~ female age estimates

• male age estimates

500 Gompertz

E' von Bertalanffy E logistic: :5 400 logistic 0> ;=.978 c Q) L =694.5 mm TL ...J linear Gompertz: 00 til MSE=338.38 0 300 ;=.977 I- L =859.2 mm TL .e 00 "' MSE=365.75 01 u:: <.0 200

100

0 2 4 6 8 10 12 14 Age Estimate (years)

Figure 13. Two-line eelpoul growth models fit to otolith age data for all fish aged using sectioned otolillls (n = 242). Each model is shown along with available inlormalion to \]etermine how well each model fits. Males and females are plotted using di!ferent symbols to show the similarity in growth. 18,------~ 16 immature testes 14 12 10 8 6 4 2 0 A. 20,------~ 18- apparently-mature testes 16

(f) 14- Q) t1l 12 !: 10- ~ 8- z 6- 4- 2- 1111 04-~.--r-,,,--,,--r-.--r-r,r-.-,-~. T T T T I B. 4.------~ 3 spent

2

0 I I m ' en m en rn en en rn rn en en en G"l G"l en en GJ G"l en en en G"l ,._ ~ l() G"l <'? 1,() 1'- G"l ~ <'? 1,() 1'- "'en M GJ <'? 1'- en ~ M c. N N N C\J N M M M M M "' l.i) 1..'1 l() C'1

Figure 14. Number of male eelpouts with: a) immature testes (n = 119); b) apparentiy-mature testes (n 132); and c) spent testes (n = 5) determined through visual estimates.

70 8 6 immature ovaries 4 2

A. 0 I 10

8 small eggs 6 4 2 s.o 10

ID 8- medium eggs 'E"' E 6- ~

4 !~ "'"' 0 I I I I I I I I I I I I I I I I III I I I I E. Q) Q) Q) Q) Q) C> Q) C> Q) Q) Q) 0> C'> O'l m O'l O'l C'> 0> C'> ~ M 1"- C) ~ M l[") I'- ....,. M U1 ....,.1"- M l{) 1"- C> N "' "'N N M M M M "' "' "' U1 U1 lD "'U"l Ll"l

Figure 15. Number of female eelpouts with: a) immature ovaries (n 22); b) small eggs (n = 48); c) medium eggs (n = 42); d) large eggs (n = 1); and e) spent determined through visual estimates.

71 20,------~ 16- 12- 414 mm TL 8- total fecundity "' 215 eggs 4- l11 0 I I I I I I I I I I I I I I I I J I I I 1 I I I I I I I l I I I I I I 1 i I I 1 1 1 1

16 12 8- 443 mm TL 4- total fecundity = 329 eggs I I IIIII 0 ''' i i I l I ! I I l I I I I I I I l I I I I I j I I l I l l I ! I j I l j I I I j j I

10 Ul Cl 8 OJ Ill 6 460 mm TL 0 4 total fecundity= 238 mm TL zci 2 0 I I I I I I I ! I I I I I I I I I I I t I I I I

10 8- 473 mm TL 6- 4- total fecundity= 281 eggs 2- Ia I 0 1 , , I l l I l I I I ••I I 1 i I l I 1 I I ! I l l I ! I I I I l l. l l I

10.-----rr-r------~ 8- 6-' 488 mm TL 4- II total fecundity= 275 eggs 2- I U111n 0 I I I I I I I I I I I I I L I I I I I I l 1 I iilllllllll!lllll 0.1 0.6 1 .1 1.6 2.1 2.6 3.1 3.6 4.1 4.6 5.1 Egg Diameter (mm)

(continued)

72 10,------,r------~ 8 496mm TL 6 total fecundity ,;, 260 eggs 4 2 O+rno~~~~~,.

16 Ul g 12- "' 8- 504 mm TL 0 total fecundity= 290 eggs 4- z0 0 II mil i i ! l l ' l ! I I I I ! I I • I I '

10,------.r-----~ 8 522 mm TL 6 total fecundity = 266 eggs 4 2

0~"1 ,1 ""'''"""""'1 >1 TT><1 ~,~.~,.-rr1 1 ..~~~~~~~~~~

6.----,r------, 4 617 mm TL total fecundity = 243 eggs 2

04;,-~,~~~.. ~~~~yy~~~Ar~ .. l.,, ... ,~l-n~.~ •.-., ,,,,,1 0.1 0.6 1.1 2.1 3.1 3.6 4.1 4.6 5.1 Egg Diameter (mm)

Figure 16. Diameter of all eggs measured {n =50 eggs per ovary) for a subsample of fish 414-617 mm TL (n = 9). Total fecundity for each female is indicated.

73 80

70- -<>-- % medium eggs

;:- 60 -+- %large eggs 0 ()) Q) ...... %spent til 50 u ()) 9 years of age ()) Q) 40 :S ·~ 1ii 30 ""0 --.l 11 years of age .j;.. oe 20

10

0 Ol Ol Ol Ol Ol en en en Ol Ol en 0> en 0> Ol en Ol 0> Ol en en Ol en (') 1.() ,... Ol (') 1.() ,... 0> ~ C') 1.() ,... 0> C') 1.() ,... ~ ~ C\J N C\J C\J C\J (') (') C') C') C') '

Figure 17. Cumulative maturity of female eelpouts shown by plolling the percent of females that contained medium eggs, large eggs, and spent ovaries of the total analys'"d lor each size category. Age estimates corresponding to the size at which each egg category begins are shown. 100.------,

=-!ll -E -ro ~ !ll .0 10- E ::J c z~ 5 ...

1~------,-,------.-,------,-,------.,------,,------.-,------4 0 2 4 6 8 10 12 14 t (lime or age estimate in years) Figure 18. Catch curves created by plotting the natural log of Nt (number of fish collected of age t) versus t (fish age in years) for all fish analysed (n =. 542). Age, or lime I, was estimated for tish not aged using age-length data for fish whose otoliths were aged. 0.9 _.,_ z = 0.316 O.B

0.7 --..... z =0.247

0.6 __..,.... z =0.203

~ 0.5

0.4

--1 en 0.3-

0.2

0.1

0 0 5 10 15 20 25 x (fish age in years)

Figure 19. Survivorship (lx) curves plotted using longevities of 14, 18, and 22 years and resul!ing instantaneous mortalities (z). Appendix A. Trawl information for all tows in which specimens were captured including information on how each was used for analysis. "Unknown" usually refers to information commercial fishing captains were unwilling to ~rovide. # B.b. #used for vessel trawl# date dist. fished avg. deeth site* caught feed. age/growth reero. RN M. FREEMAN 42 2-Nov-92 1.68 nm 322m crm 10 0 0 0 RN M. FREEMAN 76. 28-0ct-94 1.08 nm 480m crm 1 0 0 0 RN M. FREEMAN 120 5-Nov-94 1.05 nm 528m crm 7 0 0 0 RN M. FREEMAN 18 .22-0ct-92 .89nm 538m crm 5 0 5 5 RN M. FREEMAN 3 14-0ct-94 .85nm 560m crm 2 0 2 2 RN M. FREEMAN 102 1-Nov-94 1.03 nm 572 m crm 10 0 4 4 RN M. FREEMAN 88 30-0ct-94 1.05 nm 586 m crm 1 1 1 1 RN M. FREEMAN 18 17-0ct-94 .97 nm 588 m crm 6 0 0 0 RNPTSUR NA 6-0ct-92 unknown 600-650 m cc 2 2 2 2 RN M. FREEMAN 46 3-Nov-92 .98 nm 606 m crm 7 0 0 0 ""' RN M. FREEMAN 64 8-Nov-92 .90 nm 618 m crm 17 6 17 17 RN M. FREEMAN 121 5-Nov-94 1.02 nm 620m crm 2 0 0 0 RN M. FREEMAN 11 16-0ct-94 1.10 nm 632 m crm 1 0 0 0 RN M. FREEMAN 44 3-Nov-92 .95nm 636m crm 4 3 4 4 RN M. FREEMAN 21 23-0ct-92 1.02 nm 642m crm 15 5 15 15 RN M. FREEMAN 101 1-Nov-94 1.08 nm 658m crm 1 0 0 0 RN M. FREEMAN 66 24-0ct-94 1.02 nm 668m crm 2 0 2 2 RN M. FREEMAN 51 5-Nov-92 1.03 nm 682 m crm 3 0 3 3 RN M. FREEMAN 75 28-0ct-94 1.00 nm 684m crm 6 0 1 1 RN M. FREEMAN 26 25-0ct-92 .99nm 692m crm 7 0 7 7 RN M. FREEMAN 19 17 -Oct-94 1.13 nm 694 m crm 8 0 5 5 RN M. FREEMAN 52 22-0ct-94 1.04nm 700 m crm 4 1 1 1 RN M. FREEMAN 69 10-Nov-92 1.00 nm 702 m crm 9 6 9 9 RN M. FREEMAN 38 20-0ct-94 1.02 nm 704m crm 5 1 1 1 RN M. FREEMAN 133 7-Nov-94 .B8nm 704m crm 2 0 0 0 RN M. FREEMAN 26 18-0ct-94 .9Bnm 706m crm 18 0 0 0 RN M. FREEMAN 3 18-0ct-92 1.01 nm 710 m crm 10 0 0 0 RN M. FREEMAN 60 24-0ct-94 1.03 nm 710 m crm 3 0 1 1 RN M. FREEMAN 9 19-0ct-92 1.10 nm 716 m crm 20 1 5 5 RN M. FREEMAN 4 15-0ct-94 1.04 nm 720 m crm 10 0 6 6 RN M. FREEMAN 79. 11-Nov-92 .81 nm 726m crm 6 0 6 6 RN M. FREEMAN 127 6-Nov-94 1.03 nm 728 m crm 1 0 0 0 RN M. FREEMAN 106 2-Nov-94 1.15 nm 730 m crm 9 0 0 0 FN MARIAN ANN 4 B-Sep-93 unknown 740 m cc 4 4 4 4 FN GLN FLEECE PC2-1 23-Sep-91 .94nm 750 m cc 1 1 1 1 RN M. FREEMAN 49 4-Nov-92 1.21 nm 752 m crm 3 0 0 0 RN M. FREEMAN 75 11-Nov-92 1.29nm 756 m crm 4 0 4 4 RN M. FREEMAN 38 1-Nov-92 .98nm 766m crm 2 0 0 0 RN M. FREEMAN 80 29-0ct-94 1.05 nm 7BOm crm 2 0 0 0 """co RN M. FREEMAN 45 21-0ct-94 .97 nm 786 m crm 3 0 0 0 RN M. FREEMAN 87 30-0ct-94 1.07 nm 788 m crm 1 0 0 0 RN D.S. JORDAN 14 23-Nov-92 2.06 nm BOOm cc 1 1 1 1 FN C. C. & GLOR 1 6-Aug-93 unknown 800 m cc 1 1 1 1 RN M. FREEMAN 134 7-Nov-94 1.98 nm 822m crm 9 0 0 0 RN M. FREEMAN 25 25-0ct-92 1.90 nm 846m crm 2 0 0 0 RN M. FREEMAN 25 18-0ct-94 2.16 nm 848 m crm 6 0 0 0 RN M. FREEMAN 39 1-Nov-92 1.71 nm B52m crm 74 10 13 13 RN M. FREEMAN 52 5-Nov-92 2.00 nm 856m crm 2 0 0 0 RN M. FREEMAN 5 15-0ct-94 2.19 nm B60m crm 9 0 0 0 RN M. FREEMAN 11 20-0ct-92 1.98 nm 86Bm crm 17 0 5 5 RN M. FREEMAN 65 9-Nov-92 2.00 nm 872m crm 32 31 32 32 RN M. FREEMAN 126 6-Nov-94 2.28nm 878 m crm 6 0 0 0 RN M. FREEMAN 74 28-0ct-94 1.98nm 886 m crm 2 0 1 1 RN M. FREEMAN 59 24-0ct-94 1.88 nm 888m crm 36 0 0 0 RN M. FREEMAN 47 4-Nov-92 2.06 nm 896 m crm 2 2 2 2 RN M. FREEMAN 43 3-Nov-92 1.85 nm 898m crm 3 0 3 3 RN M. FREEMAN 17 22-0ct-92 1.74 nm 900m crm 16 0 16 16 RN M. FREEMAN 39 20-0ct-94 2.01 nm 906 m crm 2 0 0 0 RN M. FREEMAN 10 16-0ct-94 2.34 nm 908m crm 6 0 0 0 RN M. FREEMAN 67 24-0ct-94 2.19 nm 908m crm 5 0 0 0 RN M. FREEMAN 20 17-0ct-94 2.07 nm 912 m crm 4 0 0 0 RN M. FREEMAN 55 6-Nov-92 1.99 nm 916 m crm 3 0 0 0 RN M. FREEMAN 59 7-Nov-92 2.02 nm 918 m crm 4 5 5 5 RN M. FREEMAN 53 22-0ct-94 2.18 nm 918 m crm 1 0 0 0 RN M. FREEMAN 122 5-Nov-94 1.99 nm 926 m crm 2 0 0 0 RN M. FREEMAN 12 20-0ct-92 1.85 nm 934m crm 32 8 32 32 RN M. FREEMAN 81 29-0ct-94 2.08 nm 948m crm 10 0 1 1 RN M. FREEMAN 82 29-0ct-94 2.42nm 948 m crm 6 0 0 0 -.j

82 MF 48 3 545 M 5 2.5 0.0702 MF 65 4 236 NA 2.6 1.2 0.012 MF 65 5 203 NA 2.2 1 0.0083 MF 65 6 242 NA 2.5 1.2 0.0107 MF 65 7 236 NA 2.4 1.1 0.0107 MF 65 8 344 F 3 1.4 0.0215 MF 65 9 206 NA 2.2 2 0.008 MF 65 10 217 NA 2.4 1.2 0.0106 MF 65 11 190 NA 2.1 0.9 0.0071 MF 65 12 142 NA 1.7 0.8 0.0039 MF 65 13 147 NA 2 0.7 0.004 MF 65 14 159 NA 1.8 0.8 0.0046 MF 65 15 236 NA 2.5 1.1 0.0111 MF 65 16 237 NA 2.3 1.1 00099 MF 65 17 211 NA 2.4 1.1 0.0098 MF 65 18 198 NA 2.2 1 0.0081 MF 65 19 174 NA 2.1 0.9 0.0061 MF 65 20 174 NA 2.1 0.0069 MF 65 21 142 NA 1.6 0 ..0036 MF 65 22 182 NA 2.2 1 0.0066 MF 65 23 137 NA 1.7 0.0034 MF 65 24 186 NA 2.2 1 0.0077 MF 65 25 144 NA 1.8 0.8 0.0038 MF 65 26 342 M 3 1.6 0.023 MF 65 27 174 NA 2.1 0.9 0.006 MF 65 28 173 NA 2 0.9 0.0062 MF 65 29 210 NA 2.4 1.1 0.0096 MF 65 30. 184 NA 2.3 1 0.0075 MF 65 31 128 NA 1.6 0.7 0.0028 MF 65 32 283 NA 2.6 0.0154 MF 65 33 390 M 3.1 1.7 0.0253 MF 65 34 216 NA 2.4 1.1 0.0091 MF 65 35 338 M 2.8 1.6 0.0208 MF 9 36 427 M 3.5 2 0.0338 MF 9 37 339 M 2.8 1.6 0.0179 MF 9 38 488 M 3.5 2.1 0.0392 MF 9 39 508 F 4.5 2.2 0.0487 MF 9 40 575 M 4.5 0.0583 MF 53 41 356 M 2.9 1.7 0.0202

83 MF 81 42 520 F 3.7 2 0.0429 MF 81 43 557 M 4.7 2.2 0.0656 MF 78 44 239 M 2.2 1.3 0.0108 MF 78 45 364 M 2.9 0.0227 MF 78 46 383 M 3.2 1.9 0.027 MF 78 47 382 M 2.9 1.4 0.0219 MF 78 48 328 M 3.1 1.7 00227 MF 78 49 380 M 3.3 1.8 0.0266 MF 78 50 394 M 3.3 1.8 0.0296 MF 78 51 565 M 4.5 2.1 0.0497 MF 78 52 482 F 0.0373 MF 59 53 246 NA 0.0106 MF 59 54 321 NA 0.0197 MF 59 55 278 NA 0.0155 MF 59 56 192 NA 0.007 MF 59 57 211 F 0.008 MF 18 58 582 F 0.0437 MF 18 59 448 F 0.0312 MF 18 60 494 M o:o4 MF 18 61 509 F 0.0461 MF 18 62 592 M 0.0585 MF 76 63 537 F 0.0573 MF 76 64 493 F 0.0403 MF 76 65 470 M 0.0334 MF 76 66 508 F 0.049 MF 76 67 460 M 0.0416 MF 76 68 434 M 0.0303 MF 76 69-, 430 M 0.0302 MF 76 70 404 M 0 0328 MF 76 71 444 M 0.0323 MF 76 72 333 NA 0.0227 MF 76 73 335 NA 0.0215 MF 76 74 328 M 0.0218 MF 76 75 306 NA 0.0172 MF 76 76 250 M 0.0125 MF 69 77 505 F 0.0478 MF 69 78 498 M 0.0337 MF 69 79 411 M 0.0278 MF 69 80 351 M 0.0254

84 MF 69 81 372 M 0.0227 MF 69 82 323 M 0.0196 MF 69 83 267 M 0.0128 MF 69 84 260 M 0.0151 MF 69 85 179 M 0.0068 MF 13 86 535 F 0.0283 MF 13 87 342 M 0.0273 MF 13 88 318 F 0.0187 MF 13 90 511 M 0.051 MF 13 91 496 M 0.043 MF 13 92 131 NA 0.0026 MF 13 93 333 M 0.018 MF 13 94 415 M 0.0382 MF 13 95 457 M 0.0412 MF 13 96 518 M 0.0478 MF 13 97 523 F 0.0519 MF 13 98 546 F 0.0436 MF 13 99 442 F 0.0366 MF 13 100 397 F 0:026 MF 13 101 397 M 0.0338 MF 13 102 370 M 0.0263 MF 13 103 394 F 0.0334 MF 13 104 325 M 0.0223 MF 13 105 129 NA 0.0025 MF 13 106 168 NA 0.0055 MF 13 107 137 NA 0.0026 MF 68 108 189 NA 0.0072 MF 68 109 329 F 0.0172 MF 68 110 246 F 0.0127 MF 68 111 302 M 0.0202 MF 68 112 582 M 0.047 MF 68 113 485 F 0.0417 MF 68 114 476 F 0.0431 MF 77 115 562 F 0.0506 MF 77 116 530 M 0.0584 MF 77 117 450 F 0.0353 MF 77 118 355 M 0.0268 MF 77 119 530? F 0.0429 MF 77 120 440 M 0.0345

85 MF 77 121 455 M 0.0362 MF 77 122 421 M 0.0263 MF 77 123 414 M 0.0298 MF 77 124 406 M 0.0403 MF 77 125 310? M 00265 MF 77 126 334 M 0.0207 MF 77 127 303 M 0.0193 MF 77 128 235 M 0.011 MF 77 129 183 NA 0.0067 MF 77 130 158 NA 0.0044 MF 77 131 125 NA 0.0019 MF 77 132 537 F 0.0581 MF 77 134 481 M 0.0445 MF 21 135 570 M 0.0663 MF 21 136 500 F 0.0435 MF 21 137 536 F 0.057 MF 21 138 473 M 00432 MF 21 139 500 M 0.0395 MF 21 140 536 F 0.0592 MF 21 141 511 F 0.0442 MF 21 142 434 F 0.0396 MF 21 144 476 M 0.0474 MF 21 145 424 M 0.0274 MF 21 146 373 F 0.025 MF 21 147 377 M 0.026 MF 21 148 375 M 0.029 MF 21 149 378 F 0.0267 MF 57 150 151 NA 0.003 MF 57 151 151 NA 0.0019 MF 57 152 NA NA 0.0084 MF 57 153 247 NA 0.0107 MF 57 154 541 M 0.0494 MF 57 155 545 F 0.0532 MF 57 156 480 M 0.0446 MF 57 157 550 M 0.0572 MF 57 158 491 M 0.0427 MF 57 159 455 M 0.032 MF 57 160 480 M 0.048 MF 57 161 488 M 0.0393

86 MF 57 163 457 M 0.0538 MF 57 164 468 F 0.0342 MF 57 165 480 M 0.0364 MF 57 166 458 F 0.0426 MF 57 167 431 M 0.0308 MF 57 168 380 F 00306 MF 57 169 357 M 0.0255 MF 57 170 135 NA 0.0024 MF 24 171 515 M? 0.0447 MF 24 172 556 M 0.0518 MF 24 173 326 M 0.0166 MF 24 174 377 M 0.0259 MF 24 175 360 M 0.0242 MF 24 176 349 F 0.0268 MF 24 177 395 M 0.0267 MF 24 178 308 F 0.0217 MF 24 179 246 M 0.0095 MF 24 180 211 NA 0.0092 MF 24 181 187 NA 0.006 MF 24 182 150 NA 0:0045 MF 44 183 468 M 0.0335 MF 44 184 550 M 0.055 MF 44 185 538 F 0.0571 MF 44 186 272 F? 0.0131 MF 41 187 97 NA 0.0002 MF 41 188 525 M 0.0424 MF 41 189 445 M 0.0314 MF 41 190 513 M 0.0427 MF 41 191 450 F 0.0323 MF 41 192 134 NA 0.0029 MF 41 193 355 M 0.026 MF 41 194 137 NA 0.0006 MF 41 195 531 M 0.0494 MF 41 196 475 M 0.0455 MF 41 197 479 M 0.0432 MF 41 198 97 NA 0.0002 MF 41 199 460 M 0.0402 MF 41 200 70-80? 0.0001 MF 41 201 445 M 0.0375

87 MF 41 202 480 F 0.0508 MF 41 203 528 F 0.0428 MF 41 204 80? 0.0002 MF 41 205 80? 0.0002 MF 41 206 459 F 0.0378 MF 41 207 506 M 0.0442 MF 41 208 496 F 0.0469 MF 41 209 427 F 00213 MF 41 210 468 M 0.0322 MF 41 211 265 M 0.0149 MF 41 212 274 M 0.0152 MF 41 213 90? M 0.0001 MF 41 214 185 NA 0.0158 MF 41 215 164 NA 0.0039 MF 23 230 327 M 0.0188 MF 23 231 426 M 0.0296 MF 23 232 337 M 0.0233 MF 23 233 353 F 0.0202 MF 23 234 302 M 0.{)1 95 MF 23 235 294 F 0.0195 MF 23 236 230 M 0.011 MF 23 237 350 M 0.028 MF 23 238 285 F 0.0165 MF 23 239 202 NA 0.0091 MF 23 240 200 NA 0.0073 MF 23 241 205 NA 0.0085 MF 23 242 161 NA 0.0064 MF 23 243. 179 NA 0.0066 MF 43 244 189 NA 0.0069 MF 43 245 206 NA 0.0084 MF 43 246 260 M 0.0143 MF 11 247 367 F 0.0258 MF 11 248 240 M 0.0111 MF 11 249 264 M 0.0126 MF 11 250 300 F 0.0151 MF 11 251 276 F 0.0126 MF 79 252 313 F 0.0205 MF 79 253 355 M 0.0195 MF 79 254 262 M 0.0137

88 MF 79 255 258 M om19 MF 79 256 264 M 0.0135 MF 79 257 199 M 0.0161 MF 51 258 247 F 0.0108 MF 51 259 395 F 0.0291 MF 51 260 550 F 0.053 MF 75 261 370 F 0.0254 MF 75 263 255 F 0.012 MF 75 264 236 F 0 0112 MF 66 265 430 M 0.0394 MF 66 266 440 F 0.0384 MF 66 267 438 F 0.0339 MF 66 268 435 F 0.0257 MF 66 269 258 F 0.021 MF 66 270 236 F 0.0113 MF 17 271 327 F 0.0223 MF 17 272 343 F 0.0187 MF 17 273 336 M 0.0203 MF 17 274 290 M 0.0161 MF 17 275 385 F 0.0374 MF 17 276 336 M 0.024 MF 17 278 235 M 0.0134 MF 17 279 231 M 0.0114 MF 17 280 229 M 0.013 MF 17 281 192 M 0.009 MF 17 282 206 M 0.0078 MF 17 283 194 M 0.0069 MF 17 284 147 NA 0.0045 MF 17 285 169 NA 0.0052 MF 17 286 145 NA 0.0042 MF 12 287 455 M 332 MF 12 288 375 M 0.0208 MF 12 289 325 F 0.0204 MF 12 291 279 F 0.0158 MF 12 292 347 M 0.0255 MF 12 293 280 M 0.0168 MF 12 294 237 M 0.0112 MF 12 295 241 F 0.0122 MF 12 296 191 F 0.0067

89 MF 12 297 196 NA 0.0085 MF 12 298 226 NA 0.0111 MF 12 299 243 M 0.0137 MF 12 300 225 M 0 0114 MF 12 301 190 F 0.0072 MF 12 302 175 NA 0.0052 MF 12 303 177 NA 00055 MF 14 304 521 M 0.0397 MF 14 305 557 NA 0.0546 MF 14 306 581 F 0.0446 MF 14 308 193 F 0.0069 MF 64 309 543 F 0.0504 MF 64 311 505 F 0.0463 MF 64 312 514 M 0.0498 MF 64 313 590 F 0.0458 MF 64 314 583 F 0.0516 MF 64 315 549 M 0.0563 MF 64 316 558 F 0.052 MF 64 317 487 M 0.0365 MF 64 318 606 M 0.0618 MF 64 319 535 F 0.0414 MF 64 320 556 F 0.0426 MF 64 321 537 M 0.0501 MF 64 322 578 M 0.0614 MF 64 323 480 F 0.0369 MF 64 324 468 M 0.0423 MF 64 325 334 M 0.0219 MF 12 32q 504 F 0.0522 MF 12 327 309 M 0.0178 MF 12 328 297 F 0.0165 MF 12 329 306 F 0.0208 MF 12 330 335 M 0.02 MF 12 332 196 F 0.007 MF 12 333 229 F 0.0101 MF 12 334 229 NA 0.0093 MF 12 335 209 M? 0.0092 MF 12 336 181 NA 0.0064 MF 12 337 192 NA 0.0062 MF 12 338 175 NA 0.0053

90 MF 12 339 162 NA 0.0061 MF 12 340 157 NA 0.0046 MF 54 341 460 M 00397 MF 54 342 508 M 0.0403 MF 54 343 425 M 0.0429 MF 54 344 383 F 0.0294 MF 54 345 388 M 0.0238 MF 54 346 120 NA 0.0001 MF 54 347 477 M 0.046 MF 54 348 363 M 0.0326 MF 54 349 360 M 0.0282 MF 54 351 394 M 0.0237 MF 54 352 114 NA 0.0001 MF 54 353 350 M 0.0246 MF 54 354 148 NA 0.0231 MF 39 355 296 M 0.0155 MF 39 356 372 M 0.0326 MF 39 357 286 F 0.0154 MF 39 358 291 M 0.0156 MF 39 359 256 F 0.0119 MF 39 360 275 F 0.0128 MF 39 361 282 M 0.0161 MF 39 362 281 M 0.014 MF 39 363 266 M 0.0103 MF 39 364 297 M 0.0199 MF 39 365 221 NA 0.0104 MF 39 366 208 NA 0.0076 MF 39 367. 225 NA 0.0074 MF 16 368 407 F 0.032 MF 16 369 390 M 0.028 MF 16 370 462 M 0.0444 MF 16 371 465 F 0.0375 MF 16 372 431 M 0.0418 MF 16 373 475 F 0.034 MF 16 374 454 M 0.0476 MF 16 375 411 M 0.0312 MF 16 376 412 F 0.0334 MF 16 377 385 F 0.0375 MF 16 378 331 F 0.0233

91 MF 16 379 388 M 0.0294 MF 16 380 360 M 0.0181 MF 16 381 286 M 0.0177 MF 26 382 525 M 0.0404 MF 26 383 564 F 0.0437 MF 26 384 498 M 0.0383 MF 26 385 426 M 0.0307 MF 26 386 477 M 0.0427 MF 26 387 547 M 0.0517 MF 26 388 461 M 0.0364

92