Scartella cristata - Amazon S3

More documents

Recommendations

Info

56 a b c d Fig. 26. Direction of current flow in the Gulf of Mexico (a,c) and on the Texas - Louisiana shelf (b, d) during non summer (a, b) and summer months (c, d). Black and white tria ngles represent northerly and southerly flow, respec tively, in b a nd d. Black circles repres ent sample sites. Gulf of Mexico c urrents adapted from Britton and Morton (1989) and Texas-Louisia na shelf currents from Cho et al. (1998). the Mexican Current can be carried at 70-100 cm/s (Sturges and Blaha 1976). These features put Texas jetties within reach of larvae traveling from the eastern or southern Gulf or Mexico even if larval duration is only 30 days. A small amount of one-way gene flow (N m
57 source for Port Aransas and South Padre Island (Fig. 26) due to the northerly current flow during summer on the Texas-Louisiana shelf (Cochrane and Kelly 1986, Britton and Morton 1989, Cho et al. 1999). The middle and lower coast have similar haplotype distribution, no difference in the among group component of variation (Φ ST ), and exchange a large number of migrants per generation (N m =55.6). These similarities suggest they share the same source population(s); however, the two sites are separated by a genetic distance (0.011) comparable to that of most other sites (Table 6). Since mismatch distributions indicate Port Aransas and South Padre Island samples were large enough to encompass the variability at each locality, it seems these sites may be in the process of evolving distinct subpopulations. Overall, this study indicates that S. cristata on Texas jetties are not yet isolated from their possible sources but are extensions of them. This is contrary to work on red drum (Sciaenops ocellatus) and red snapper (Lutjanus campechanus) that indicates a single population of each species within the Gulf (Gold et al. 1999, Heist and Gold 2000, Gold et al. 2001). Comparisons of these species with Scartella cristata should be made cautiously as both red drum and red snapper have greater potential for mixing/migrating and a greater abundance of suitable habitat throughout the Gulf. Even though larval blennies have high dispersal potential (Hunte and Côté 1989, Riginos 2000, Riginos and Nachman 2001), spatial and temporal heterogeneity of coastal habitats and nearshore Gulf waters may act to partially isolate Scartella cristata on Texas jetties both from each other and their source populations. Palumbi (1994) predicts that larvae of marine organisms probably do not “see” the marine environment as a homogenous habitat. The traditional interpretation is that this results in development of genetically structured populations in areas that do not appear isolated from one another (Palumbi 1994, Debenham et al. 2000). This does not explain low levels of genetic variation found in Ophioblennius populations throughout the Atlantic basin (Muss et al. 2001) or in intertidal sculpins on the Pacific coast of North America (Yoshiyama and Sassaman 1993). Both of these groups inhabit areas exhibiting spatial and temporal heterogeneity. Studies examining population genetics of Ophioblennius atlanticus have found that a gap in a species’ range due to lack of habitat is not sufficient to form distinct populations; whereas, a similar gap with a barrier such as a large river is (Muss et al. 2001). A similar phenomenon was observed in the blenny, Axoclinus nigricaudus, which exhibits distinct populations separated by less
Page 1 and 2:
TEMPORAL AND SPATIAL VARIABILITY OF
Page 3 and 4:
3 ABSTRACT Temporal and Spatial Var
Page 5 and 6: 5 ACKNOWLEDGMENTS No journey of dis
Page 7 and 8: 7 and Moore (1998) indicate that Hy
Page 9 and 10: 9 and larvae of organisms that must
Page 11 and 12: 11 METHODS Study Areas Blenny assem
Page 13 and 14: 13 29° 18.8’ 29° 16.2’ Galves
Page 15 and 16: 15 each worked a different 15-m tra
Page 17 and 18: 17 for the same time period by the
Page 19 and 20: 19 μL of Proteinase K (10mg/ml) an
Page 21 and 22: 21 where n is the total number of b
Page 23 and 24: 23 RESULTS Habitat Characterization
Page 25 and 26: 25 the Galveston beachfront were la
Page 27 and 28: 27 Species Composition A total of 4
Page 29 and 30: 29 and declined quickly by mid wint
Page 31 and 32: 31 60 n=195 50 TL (mm) 40 30 n=1867
Page 33 and 34: 33 Hypsoblennius hentz and Hypsoble
Page 35 and 36: 35 0.8 0.7 H’ J’ H’ and J’
Page 37 and 38: 37 Mean age of individuals from the
Page 39 and 40: 39 2.5 2.0 1999 n=52 1.5 1.0 0.5 %
Page 41 and 42: 41 100 80 SLOPE INT ERCE PT R 2 Gal
Page 43 and 44: 43 elated haplotypes (B, D, E) acco
Page 45 and 46: 45 A H I H F D D C F Florida n=9 B
Page 47 and 48: 47 45 Florida n=9 45 Port Aransas n
Page 49 and 50: 49 during early life stages of thes
Page 51 and 52: 51 on these jetties exhibited a fai
Page 53 and 54: 53 Hypsoblennius ionthas=2.82 mm (C
Page 55: 55 Scartella cristata is a wide-ran
Page 59 and 60: 59 The subpopulations Scartella cri
Page 61 and 62: 61 more robust population. The catc
Page 63 and 64: 63 The last comprehensive survey in
Page 65 and 66: 65 on why this species is so abunda
Page 67 and 68: 67 Crabtree RE, Middaugh DP (1982)
Page 69 and 70: 69 Hubbs CL (1939) The characters a
Page 71 and 72: 71 Santos RS, Nash RDM (1996) Seaso
Page 73 and 74: APPENDIX A 73
Page 75 and 76: 75 100 100 75 NOVEMBER 2000 n=7 75
Page 77 and 78: 77 100 100 75 NOVEMBER 2000 n=3 75
Page 79 and 80: 79 100 100 75 MAY 2000 n=23 75 AUGU
Page 81 and 82: 81 100 JUNE 2001 n=525 100 AUGUST 2
Page 83 and 84: 83 100 100 75 FEBRUARY 2001 n=7 75
Page 85 and 86: 85 100 75 JULY 2000 n=81 100 75 OCT
Page 87 and 88: 87 100 100 75 MARCH 2001 n=1 75 JUN
Page 89 and 90: 89 100 100 75 JUNE 2001 n=7 75 AUGU
Page 91 and 92: 91 APPENDIX B. Sequences for each h
Page 93 and 94: 93 HAPLOTYPE K CTGAC_TTGAAAAGTTGGGA
Page 95 and 96: 95 HAPLOTYPE V CTGCC_TTTAAAAGTT_GGA
show all

Scartella cristata - Amazon S3

Create successful ePaper yourself

Delete template?

Save as template?