{"id":344,"date":"2015-08-05T20:26:23","date_gmt":"2015-08-05T20:26:23","guid":{"rendered":"http:\/\/sites.berry.edu\/jgraham\/?page_id=344"},"modified":"2015-08-26T12:00:52","modified_gmt":"2015-08-26T12:00:52","slug":"comparative-ecology-of-blackwater-fishes-in-the-new-jersey-pine-barrens","status":"publish","type":"page","link":"https:\/\/sites.berry.edu\/jgraham\/comparative-ecology-of-blackwater-fishes-in-the-new-jersey-pine-barrens\/","title":{"rendered":"Comparative Ecology of Blackwater Fishes in the New Jersey Pine Barrens"},"content":{"rendered":"<p>The fishes of the Pine Barrens are beautiful and distinctive.\u00a0 They include the rare blackbanded sunfish (<i>Enneacanthus chaetodon<\/i>), the shy swamp darter (<i>Etheostoma fusiforme<\/i>), and the unusual pirate perch (<i>Aphredoderus sayanus<\/i>).\u00a0 These species, which are so characteristic of blackwaters on the Atlantic Coastal Plain, rarely occur in nearby clearwaters.<\/p>\n<p>Blackwaters have high concentrations of humic substances, which stain the water dark brown.\u00a0 The humic substances come from the decomposition of lignin, the molecule that makes woody plants woody.\u00a0 In the Pine Barrens, much of the humic substances come from lignin in pine needles.\u00a0 Humic substances interfere with the transmission of light through water, and so floating and emergent macrophytes are the most important primary producers in blackwaters.<\/p>\n<p>Most blackwaters are also acidic.\u00a0 The Pine Barrens lies on the Cohansey Sand, a sedimentary deposit having very low buffering capacity.\u00a0 Thus, Pine Barrens blackwaters range in pH from 3.7 (acidic) to 6.7 (nearly neutral).<\/p>\n<p><img decoding=\"async\" title=\"\" src=\"http:\/\/facultyweb.berry.edu\/jgraham\/enneacanth.jpg\" alt=\"\" align=\"middle\" \/> \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Banded, bluespotted, and blackbanded sunfish.<\/p>\n<p>Three small sunfishes of the genus <i>Enneacanthus<\/i> offer a glimpse into the adaptations of fishes to acidic blackwaters.\u00a0 For example, the banded sunfish (<i>E. obesus<\/i>) is nearly restricted to acidic blackwaters.\u00a0 In contrast, the very similar bluespotted sunfish (<i>E. gloriosus<\/i>) is widely distributed in both clearwaters and blackwaters.\u00a0 When these two species co-occur in the same pond, they utilize different microhabitats.\u00a0 The banded sunfish occurs in shallow water having dense cover, especially submerged sphagnum moss.\u00a0 It spends much of its time picking invertebrates from the surfaces of plants.\u00a0 The bluespotted sunfish occurs among aquatic vegetation in slightly deeper water.\u00a0 It feeds on planktonic and benthic invertebrates.\u00a0 In some ponds, the relatively clear main body of the lake will have bluespotted sunfish, while the darker backwaters will have banded sunfish.\u00a0 The third species of <i>Enneacanthus<\/i>, the blackbanded sunfish (<i>E. chaetodon<\/i>), is somewhat intermediate in geographic distribution and habitat.\u00a0 It is found in both blackwaters and clearwaters, and is more likely to be found swimming in open water than either the banded or bluespotted sunfish.<\/p>\n<p>The banded and bluespotted sunfishes are morphologically more similar early in development, as larvae, than they are as adults.\u00a0 This is Ernst von Baer&#8217;s Law of Progressive Deviation.\u00a0 One might logically expect their niches to diverge as well.\u00a0 Surprisingly, however, larval banded and bluespotted sunfish are more dissimilar in their diet than are the adults.\u00a0 Larval bluespotted sunfish feed on open water invertberates, such as the cladoceran <i>Bosmina longispina,<\/i> while larval banded sunfish feed on attached invertebrates, such as the cladoceran <i>Sida crystallina<\/i> (Graham 1985).<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/facultyweb.berry.edu\/jgraham\/Larva.jpg\" alt=\"\" width=\"331\" height=\"250\" \/><br \/>\nMorphological measurements on <i>Enneacanthus<\/i><br \/>\n<img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/facultyweb.berry.edu\/jgraham\/wasp2.jpg\" alt=\"\" width=\"309\" height=\"250\" \/><br \/>\nStomach contents of <i>Enneacanthus obesus<\/i><br \/>\nAquatic wasp and copepod<\/p>\n<p>It is often claimed that species diversity of fishes is lower in acidic blackwaters.\u00a0 But the effect of pH on species diversity of native fishes in New Jersey lakes and ponds is statistically insignificant (Graham 1995).\u00a0 In contrast, pH has a highly significant effect on the species diversity of exotic species, such as bluegill and largemouth bass.\u00a0 Exotic species have been unable to invade acidic blackwaters.<\/p>\n<p>&nbsp;<\/p>\n<p>References<\/p>\n<p>Graham, J. H. 1978. Factors affecting the distribution of sunfishes (Centrarchidae) in Southern New Jersey.\u00a0 M.Sc. Thesis, Rutgers University, Camden, NJ.<\/p>\n<p>Graham, J. H. 1986. Niche ontogeny and progressive deviation in two congeneric sunfishes, <i>Enneacanthus obesus<\/i> and <i>E. gloriosus<\/i> (Centrarchidae). Ph.D. Dissertation, Rutgers University, New Brunswick, NJ.<\/p>\n<p>Graham, J. H. 1989. Foraging by sunfishes in a bog lake. Pages 517-527 <i>In<\/i> R. R. Sharitz and J. W. Gibbons (Eds.) Freshwater wetlands and wildlife. CONF-8603101, DOE Symposium Series No. 61, USDOE Office of Scientific and Technical Information, Oak Ridge, TN.<\/p>\n<p>Graham, J. H. 1993.\u00a0 Species diversity of fishes in naturally acidic lakes in New Jersey. Transactions of the American Fisheries Society 122: 1043-1057.<\/p>\n<p>Graham, J. H. and J. D. Felley. 1983.\u00a0 Genomic coadaptation and developmental stability within introgressed populations of <i>Enneacanthus gloriosus<\/i> and <i>E. obesus<\/i> (Pisces, Centrarchidae) Evolution 39: 104-114.<\/p>\n<p>Graham, J. H. and R. W. Hastings. 1984. Distributional patterns of sunfishes (Centrarchidae) on the New Jersey Coastal Plain. Environmental Biology of Fishes 10: 137-148.<\/p>\n<p>Graham, J. H. and R. C. Vrijenhoek. 1988.\u00a0 Detrended correspondence analysis of dietary data. Transactions of the American Fisheries Society 117: 29-36.<\/p>\n<hr noshade=\"noshade\" width=\"100%\" \/>\n<p>Last Updated\u00a06 August 2015<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The fishes of the Pine Barrens are beautiful and distinctive.\u00a0 They include the rare blackbanded sunfish (Enneacanthus chaetodon), the shy swamp darter (Etheostoma fusiforme), and the unusual pirate perch (Aphredoderus [&hellip;]<\/p>\n","protected":false},"author":29,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-344","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/pages\/344","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/users\/29"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/comments?post=344"}],"version-history":[{"count":2,"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/pages\/344\/revisions"}],"predecessor-version":[{"id":387,"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/pages\/344\/revisions\/387"}],"wp:attachment":[{"href":"https:\/\/sites.berry.edu\/jgraham\/wp-json\/wp\/v2\/media?parent=344"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}