Coloniality has evolved once in Stolidobranch Ascidians

Ascidians exhibit a rich array of body plans and life history strategies. Colonial species typically consist of zooids embedded in a common test and brood large, fully developed larvae, while solitary species live singly and usually free-spawn eggs that develop into small, undifferentiated larvae. Ascidians in the order Stolidobranchia include both colonial and solitary species, as well as several species with intermediate morphologies. These include social species, which are colonial but do not live completely embedded in a common test, and a few solitary species that brood embryos and larvae until they are competent to metamorphose. We examined how many times coloniality has evolved within the Stolidobranchia, with phylogenetic analyses using full-length 18S rDNA and partial cytochrome oxidase B sequences for taxa in the families Molgulidae, Styelidae, and Pyuridae. Tunicata orders Phlebobranchia and Stolidobranchia are sister groups, and the family Molgulidae is a monophyletic group and should be raised to the subordinal level, as shown previously by analyses from this lab with partial 18S sequences. In contrast to previous studies, styelids and pyurids are separated into monophyletic groups by ML and Bayesian analyses. We show a single clade within the family Styelidae that contains two colonial (compound) botryllid species, a Symplegma (colonial compound), a colonial (social) species Metandrocarpa taylori, as well as four solitary species, thus confirming that the botryllids are a subfamily of the Styelidae. These results suggest that the ancestor of the Stolidobranchia was solitary and that coloniality has evolved only once within this clade of ascidians. Further phylogenetic analyses of aplousobranch and phlebobranch ascidians will be necessary to understand the number of times that coloniality has evolved within the class Ascidiacea.     

Evolution and development of budding by stem cells: Ascidian coloniality as a case study

The evolution of budding in metazoans is not well understood on a mechanistic level, but is an important developmental process. We examine the evolution of coloniality in ascidians, contrasting the life histories of solitary and colonial forms with a focus on the cellular and developmental basis of the evolution of budding. Tunicates are an excellent group to study colonial transitions, as all solitary larvae develop with determinant and invariant cleavage patterns, but colonial species show robust developmental flexibility during larval development. We propose that acquiring new stem cell lineages in the larvae may be a preadaptation necessary for the evolution of budding. Brooding in colonial ascidians allows increased egg size, which in turn allows greater flexibility in the specification of cells and cell numbers in late embryonic and pre-metamorphic larval stages. We review hypotheses for changes in stem cell lineages in colonial species, describe what the current data suggest about the evolution of budding, and discuss where we believe further studies will be most fruitful.     

Resource allocation in ascidians: reproductive investment vs. other life-history traits

Abstract. To determine patterns of resource allocation among ascidians, we studied 16 colonial and solitary species. We measured investment in reproductive vs. structural material (tunic) both in terms of weight and caloric content, as well as fecundity and degree of larval complexity in the colonial species. Measurements in weight and caloric content were highly correlated in the species studied. A wide range of investment in reproduction was found. Tunic production was related to the growth form of the species, stolonic and solitary species investing less in tunic than massive species, but no significant relationship was found between investment in tunic production vs. reproduction. In colonial species we found that in species with small zooid size, the reproductive investment per zooid was significantly higher. There was a significant negative relationship between investment in reproduction and fecundity. We also found a significant relationship between reproductive investment and larval complexity. The overall trend was that species with low fecundity had large complex larvae and invested the most energy in reproduction.     

Convergent evolution of locomotor morphology but not performance in gymnotiform swimmers

Convergent evolution of a novel locomotor strategy implies that a fitness benefit may be associated with the new gait. Opportunities to study this phenomenon are often constrained by a lack of transitional taxa, but teleost fishes offer examples of extant species across such evolutionary shifts in gait. For instance, one species from Osteoglossiformes and the entire order of Gymnotiformes independently evolved a novel gait, gymnotiform locomotion, where thrust is produced by the undulation of an elongate anal fin. Here, we investigate whether this convergence in gait is also associated with similarities in shape, burst swimming abilities, and/or steady‐swimming energetics. Specifically, we measured body and fin morphology of fish within Gymnotiformes and Osteoglossiformes, along with closely related Siluriformes and Cypriniformes, to examine the link between gymnotiform locomotion and morphology in a phylogenetic context. Second, we tested the burst swimming capabilities and oxygen consumption during endurance swimming of a subset of the same gymnotiform, osteoglossiform, and cypriniform species, including “transitional” Osteoglossiformes that exhibit intermediate gaits, to determine whether the evolution of this specialized gait is associated with a change in either of these performance metrics. Our results suggest that convergence on the gymnotiform gait is associated with morphological convergence, but does not constrain a fish's maximum sprinting speeds or their energetic demands during steady swimming.     

Does predation select for or against avian coloniality? A comparative analysis

Some studies have supported predation as a selective pressure contributing to the evolution of coloniality. However, evidence also exists that colonies attract predators, selecting against colonial breeding. Using comparative analyses, we tested the reduced predation hypothesis that individuals aggregate into colonies for protection, and the opposite hypothesis, that breeding aggregations increase predation risk. We used locational and physical characteristics of nests to estimate levels of species' vulnerability to predation. We analysed the Ciconiiformes, a large avian order with the highest prevalence of coloniality, using Pagel's general method of comparative analysis for discrete variables. A common requirement of both hypotheses, that there is correlated evolution between coloniality and vulnerability to predation, was fulfilled in our data set of 363 species. The main predictions of the reduced predation hypothesis were not supported, namely that (1) solitary/vulnerable species are more prone to become colonial than solitary/protected species and (2) colonial/protected species are more likely to evolve towards vulnerability than solitary/protected species. In contrast, the main predictions of the increased predation hypothesis were supported, namely that colonial/vulnerable species are more prone (1) to become protected than solitary/vulnerable species and/or (2) to become solitary than colonial/protected species. This suggests that the colonial/vulnerable state is especially exposed to predation as coloniality may often attract predators rather than provide safety.     

Getting in shape: adaptation and phylogenetic inertia in morphology of Australian anuran larvae

The external morphology of frog larvae is predicted to vary among habitats, for a variety of functional reasons. I performed a phylogenetic comparative study to test whether correlations between habitat and the shape of the tadpole and its oral disc are adaptive in 82 species from south‐eastern Australia in the families Hylidae and Myobatrachidae. Habitat distributions and phylogenetic relationships were compiled from the literature and shape was quantified using geometric morphometric analysis of published drawings. Results indicate that shape evolved towards different optima in different habitats while also showing appreciable levels of phylogenetic inertia. Within myobatrachids, evolution of terrestrial tadpoles was associated with a short and shallow head/body and a shallow tail. In aquatic species, the use of benthic microhabitats was correlated with a long shallow tail, dorsal eye position, shallow head/body and ventral mouth with robust jaw sheaths. Even traits with evidence for adaptation evolved slowly in response to habitat shifts, usually requiring ≥10 million years to evolve half‐way to a new optimum. Although these findings support adaptive evolution of tadpole body form, they also highlight a strong influence of ancestral character states and indicate that phenotypes in extant species are partly maladaptive.     

Patterns of caudal-autotomy evolution in lizards

Using comparative techniques to account for phylogenetic effects, I examined patterns of evolution of caudal autotomy and foraging in 39 lizard species to test the hypothesis that caudal autotomy has co-evolved with morphology, locomotor performance, and foraging behaviour. There were significant positive associations between evolution of the point on the tail (distance from cloaca) at which tail loss occurs (an indirect measure of caudal autotomy) and evolution of each of the following: tail length, caudifemoralis longus (CFL) muscle length, and jump distance. The correlation with the evolution of sprint speed approached significance. These relationships primarily were due to the influence of tail-length evolution on autotomy-point evolution. With the effect of tail-length evolution removed, autotomy-point evolution was negatively correlated with the evolution of tail-loss frequency. The CFL restricts tail loss to portions of the tail posterior to the most distal point of its insertion in the tail. In addition, with the effect of tail-length evolution removed, CFL length co-evolved with sprint speed. These results indicate that tail morphology has co-evolved with caudal autotomy such that the evolution of the CFL has reduced caudal autotomy in certain groups of lizards.
Ambush foraging, the ability to lose the tail, intermediate CFL length, and low locomotor performance (i.e. slow sprint speed and short jump distance) are hypothesized to be the ancestral conditions in lizards using outgroup rooting. The diversification of lizard taxa has resulted in some lineages moving away from ancestral character states (i.e. family Teiidae, superfamily Varanoidea), while others are very similar or identical to their ancestors (i.e. superfamily Iguania).     

Triturus newts defy the running-swimming dilemma

Conflicts between structural requirements for carrying out different ecologically relevant functions may result in a compromise phenotype that maximizes neither function. Identifying and evaluating functional trade-offs may therefore aid in understanding the evolution of organismal performance. We examined the possibility of an evolutionary trade-off between aquatic and terrestrial locomotion in females of European species of the newt genus Triturus. Biomechanical models suggest a conflict between the requirements for aquatic and terrestrial locomotion. For instance, having an elongate, slender body, a large tail, and reduced limbs should benefit undulatory swimming, but at the cost of reduced running capacity. To test the prediction of an evolutionary trade-off between swimming and running capacity, we investigated relationships between size-corrected morphology and maximum locomotor performance in females of ten species of newts. Phylogenetic comparative analyses revealed that an evolutionary trend of body elongation (increasing axilla-groin distance) is associated with a reduction in head width and forelimb length. Body elongation resulted in reduced maximum running speed, but, surprisingly, also led to a reduction in swimming speed. The evolution of longer tails was associated with an increase in maximal swimming speed. We found no evidence for an evolutionary trade-off between aquatic and terrestrial locomotor performance, probably because of the unexpected negative effect of body elongation on swimming speed. We conclude that the idea of a design conflict between aquatic and terrestrial locomotion, mediated through antagonistic effects of body elongation, does not apply to our model system.     

Phylogenetic effects, the loss of complex characters, and the evolution of development in calyptraeid gastropods

Abstract Despite considerable theoretical and empirical work on the population genetic effects of mode of development in benthic marine invertebrates, it is unclear what factors generate and maintain interspecific variation in mode of development and few studies have examined such variation in a phylogenetic context. Here I combine data on mode of development with a molecular phylogeny of 72 calyptraeid species to test the following hypotheses about the evolution of mode of development: (1) Is the loss of feeding larvae irreversible? (2) Is there a phylogenetic effect on the evolution of mode of development? (3) Do embryos of direct‐developing species lose the structures necessary for larval feeding and swimming and, if so, is the degree of embryonic modification correlated with the genetic distance between species? The results of these analyses suggest that mode of development evolves rapidly and with little phylogenetic inertia. There are three cases of the possible regain of feeding larvae, in all cases from direct development with nurse eggs. It appears that species with planktotrophic, lecithotrophic, or direct development with nurse eggs all have equal evolutionary potential and retain the possibility of subsequent evolution of a different mode of development. However, species with direct development from large yolky eggs appear to be subject to phylogenetic constraints and may not be able to subsequently evolve a different mode of development. Finally, species that have more recently evolved direct development have less highly modified embryos than older direct‐developing species. Since species with nurse eggs generally have fewer embryonic modifications than those from large yolky eggs, this embryological difference may be the underlying cause of the difference in evolutionary potential.     

Mate fidelity and coloniality in waterbirds: a comparative analysis

Increased opportunities for information are one potential benefit of sociality. We apply this idea to the advantages of colonial breeding in bird species that are typically monogamous within a breeding season but often form new pair-bonds in subsequent seasons. Individuals may benefit from nesting in colonies at high density by identifying good-quality potential alternative mates among their neighbours. The opportunities for finding a better mating option are likely to increase with colony size and density. We tested this prediction with a comparative analysis of the association between mate fidelity and coloniality in waterbirds (wading birds and seabirds), where there is wide variation in both the degree of mate retention over consecutive breeding seasons and the degree of coloniality. We used two comparative statistical analyses, one based upon generalized least squares and the other based upon a continuous-time Markov model, to test whether the pattern of association between divorce rate and degree of coloniality was evidence for correlated evolutionary change in the two characters. We found a significant and positive association between divorce rate and the degree of coloniality in waterbirds. The probable ancestral state corresponds to a combination of a high degree of coloniality with no, or weak, mate fidelity. The reconstruction of the historical pattern of character origin and evolution indicates that the transition from a high to a low degree of coloniality occurred before the transition to higher mate fidelity. Received: 5 January 1998 / Accepted: 20 April 1998     

The evolutionary transition to coloniality promotes higher blood parasitism in birds

Parasitism has been argued as one of the major costs of breeding sociality in birds. However, there is no clear evidence for an increased parasite pressure associated with the evolutionary transition from solitary to colonial breeding. I used the pairwise comparative method to test whether colonial bird species incur in a greater risk of infection and if they must to face with a greater diversity of blood parasites (Haematozoa), by comparing pairs of congeners that included one solitary and one colonial breeding species. The richness, both in terms of number of species and number of genera, as well as the prevalence of blood parasites resulted higher in colonial species than in their solitary breeding sisters, while controlling for differences in research effort and other potentially confounding effects. These results point towards higher transmission rates of blood parasites among colonial hosts. Given the detrimental effects of blood parasites on their host fitness, the higher risk of infection and the exposition to a more diverse parasite fauna may have imposed an important cost associated to the evolution of avian coloniality. This may help to explain why colonial species have larger immune system organs, as well as to explore differences in other host life history traits potentially shaped by blood parasites.     

Comparative morphology of the stolonic vessel in a didemnid ascidian and some related tissues in colonial ascidians

The stolonic vessel is a tubular projection of the epidermis from the anterior part of the abdomen in the didemnid ascidians, and the vessel has been supposed to be closely related to the stolons, vascular appendages, and the posterior ends of the abdomen in other aplousobranch ascidians. We compared the morphology of the stolonic vessels of Diplosoma virens with similar or related tissue in other colonial ascidians, e.g. stolons of Clavelina, vascular appendages of Distaplia and Eudistoma, tunic vesicle of Aplidium, and vascular ampullae of Botrylloides. The epidermis of the stolonic vessel is composed of cuboidal cells in lateral wall and columnar cells at the distal tip of the vessel. The cuboidal cells have microvilli that probably anchor the stolonic vessel to the tunic. The columnar cells contain round granules that may concern with the secretion of some tunic components. The secretion of the granules, however, could not observed in this study. The stolonic vessel of D. virens is similar in morphology to the vascular ampullae of Botrylloides and the tunic vesicle of Aplidium rather than the other tissue examined here. Since the cell morphology is supposed to reflect its function but not the phylogenetic relationship, the present study could not provide conclusive evidences to prove the homology and the phylogenetic relationship among the tubular, epidermal projections in the colonial ascidians.     

Evolution of Craniodental Correlates of Diet in African Bovidae

Establishing the relationship between craniodental morphology and dietary ecology in extant species permits inferences to be made about the ecology and biology of fossil species and the habitats they inhabited. Previous work linking diet and craniodental morphology has historically relied upon categorical classifications of diet and has not considered the phylogenetic signal (i.e., non-independence) of morphology due to shared evolutionary history. Here we use phylogenetic comparative methods to analyze the relationship between diet and eight craniodental indices for 40 species of African Bovidae using both categorical and continuous (stable carbon isotopes of enamel, δ¹³C) classifications of diet. In addition, we examine three modes of evolution that best explain interspecific variation in each of these indices, including: Brownian Motion (BM), Early Burst (EB), and Ornstein-Uhlenbeck (OU). Our results show that the hypsodonty index (HI), the length of the masseteric fossa relative to facial depth (MAS-F), and the length of the diastema relative to the total toothrow length (DIAS-TR) are the best predictors of diet among African bovids. These indices are best explained by either a BM or OU mode of evolution. Our findings have important implications for understanding the evolution of craniodental traits and reconstructing the diet of fossil mammals, especially bovids.     

A comparative study of the non-acidic chemically mediated antifoulant properties of three sympatric species of ascidians associated with seagrass habitats

The present study investigated aspects of the antifoulant properties of three sympatric species of ascidians found in seagrass habitats of the Gulf of Mexico, Southern Atlantic Ocean, and Caribbean. Field observations in Saint Joseph Bay, Florida indicate that all three species are common and that the tunic of the solitary ascidian Molgula occidentalis is often heavily fouled, while the outer surfaces of both the colonial ascidians Amaroucium stellatum and Botryllus planus are free of fouling organisms. Antifoulant activities of a suite of increasing hydrophilic organic extracts prepared from the tunic of M. occidentalis and whole colonies of A. stellatum and B. planus were measured using both sympatric microbial (bacteria) and macroinvertebrate (cyprid larvae of Balanus amphitrite) fouling organisms in laboratory bioassays. In addition, field antifoulant assays were conducted by combining organic extracts with controlled-release resin and subsequently coating this material on to acrylic rods deployed in the field for a 72 h period. Extracts of the tunic of M. occidentalis generally did not inhibit bacterial growth. The exception was the methanol extract, which inhibited growth in one of the six marine bacteria tested. Moreover, only the highest concentrations of hexane and methanol tunic extracts tested prevented attachment of cyprid larvae. Field assays revealed no antifoulant activity on rods coated with resin containing extracts of M. occidentalis. Inhibition of both microbial growth and cyprid settlement were much more pronounced in whole-organism extracts of the two colonial ascidians. Most potent were the aqueous methanol extracts of colonies of B. planus and A. stellatum which inhibited growth in five of the six marine bacteria tested. In addition, hydrophilic and lipophilic extracts of the colonial ascidians significantly inhibited attachment of cyprid larvae, in many instances across a wide range of extract concentrations. Field antifoulant assays indicated that extracts of both colonial ascidians inhibited settlement of bryozoans and barnacles. The findings indicate that the colonial ascidians B. planus and A. stellatum possess chemical antifoulant properties. In contrast, the solitary ascidian M. occidentalis appears to either tolerate fouling or possess other non-chemical mechanisms to cope with the risks associated with epibiont overgrowth.     

Ecological drivers of body size evolution and sexual size dimorphism in short‐horned grasshoppers (Orthoptera: Acrididae)

Sexual size dimorphism (SSD) is widespread and variable in nature. Although female‐biased SSD predominates among insects, the proximate ecological and evolutionary factors promoting this phenomenon remain largely unstudied. Here, we employ modern phylogenetic comparative methods on eight subfamilies of Iberian grasshoppers (85 species) to examine the validity of different models of evolution of body size and SSD and explore how they are shaped by a suite of ecological variables (habitat specialization, substrate use, altitude) and/or constrained by different evolutionary pressures (female fecundity, strength of sexual selection, length of the breeding season). Body size disparity primarily accumulated late in the history of the group and did not follow a Brownian motion pattern, indicating the existence of directional evolution for this trait. We found support for the converse of Rensch's rule (i.e. females are proportionally bigger than males in large species) across all taxa but not within the two most speciose subfamilies (Gomphocerinae and Oedipodinae), which showed an isometric pattern. Our results do not provide support for the fecundity or sexual selection hypotheses, and we did not find evidence for significant effects of habitat use. Contrary to that expected, we found that species with narrower reproductive window are less dimorphic in size than those that exhibit a longer breeding cycle, suggesting that male protandry cannot solely account for the evolution of female‐biased SSD in Orthoptera. Our study highlights the need to consider alternatives to the classical evolutionary hypotheses when trying to explain why in certain insect groups males remain small.     

COMPARATIVE EVIDENCE FOR THE EVOLUTION OF SPERM SWIMMING SPEED BY SPERM COMPETITION AND FEMALE SPERM STORAGE DURATION IN PASSERINE BIRDS

Sperm swimming speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm swimming speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm swimming speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm swimming speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm swimming speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm swimming speed.     

Morphological evolution in Tropidurinae squamates: an integrated view along a continuum of ecological settings

Variation in squamate foot morphology is likely relevant during evolutionary processes of habitat colonization because distinct surfaces differ in energetic and functional demands for locomotion. We combined new foot morphological data with published information of limb and tail lengths to investigate evolutionary changes possibly associated with the differential usage of ecological settings by Tropidurinae species. Several traits exhibited significant phylogenetic signal, and we performed conventional and phylogenetic regressions of PC scores (retained from Principal Components Analyses of morphometric traits) on continuous ecological indices. Tropidurines from sandy habitats exhibit larger foot soles, opposite to the evolution of narrow feet in species that use branches and rocks. Also, species that usually move along trunks present longer femora. This study provides evidence for morphological adaptations associated with substrate usage in Tropidurinae, and suggests that opposite morphological profiles might evolve associated with the use of surfaces energetically and functionally contrasting, possibly leading to trade‐offs.     

Early activation of adult organ differentiation during delay of metamorphosis in solitary ascidians, and consequences for juvenile growth

Abstract. Many animals have the ability to delay metamorphosis when conditions are unfavorable. This strategy carries obvious benefits, but may also result in severe consequences for lecithotrophic larvae that run low on time and energy. Precocious activation of postlarval developmental programs—so-called anticipatory development—may be adaptive and increase the survival of older, energy-depleted larvae by allowing more rapid metamorphosis. Three of six solitary ascidian species displayed extensive anticipatory development of postlarval structures, similar to heterochronies normally observed for colonial species. The capacity for anticipatory development may be linked to the length of competent period, taxonomic group, or both: members of suborder Phlebobranchia exhibited extensive anticipatory development and long competent periods, but members of suborder Stolidobranchia exhibited little or no anticipatory development and had shorter competent periods. Delay of metamorphosis of up to 3 d did not negatively impact postlarval and juvenile growth rates for any of three species tested, regardless of taxonomic group or length of competent period, although a longer, 7-d, delay resulted in slower postlarval growth in Ciona intestinalis . Anticipatory development of postlarval structures may ameliorate the negative consequences of delay of metamorphosis in C. intestinalis and Ascidiella aspersa , but Molgula socialis showed neither anticipatory development nor a negative impact of metamorphic delay on postlarval fitness. This is the first demonstration that anticipatory development of postlarval structures, normally associated only with colonial ascidians, can occur as a normal part of the development of solitary ascidians.     

The evolution of coloniality in birds in relation to food, habitat, predation, and life-history traits: a comparative analysis

Coloniality in birds has been intensively studied under the cost and benefit approach, but no general conclusion can be given concerning its evolutionary function. Here, we report on a comparative analysis carried out on 320 species of birds using the general method of comparative analysis for discrete variables and the contrast method to analyze the evolution of coloniality. Showing a mean of 23 convergences and 10 reversals, coloniality appears to be a rather labile trait. Colonial breeding appears strongly correlated with the absence of feeding territory, the aquatic habitat, and nest exposure to predators but was not correlated with changes in life-history traits (body mass and clutch size). The correlation of coloniality with the aquatic habitat is in fact explained by a strong correlation with the marine habitat. Unexpectedly, we found that the evolution toward a marine habitat in birds was contingent on coloniality and that coloniality evolved before the passage to a marine life. These results-along with the lack of transitions from the nonmarine to marine habitat in solitary species and the precedence of the loss of feeding territoriality on the passage to a marine life-contradict most of the hypotheses classically accepted to explain coloniality and suggest that we use a different framework to study this evolutionary enigma.     

Evolution of mouthbrooding and life-history correlates in the fighting fish genus Betta

The origin of and evolutionary transitions among the extraordinary diverse forms of parental care in teleost fish remain largely unknown. The "safe harbor" hypothesis predicts that the evolution from a "guarding" to a "brooding" form of care in teleost fish is associated with shifts in reproductive and life-history features such as reduced fecundity, and increased egg volume with higher parental investment. Robust phylogenetic hypotheses may help to identify evolutionary changes in key traits associated with differences in the form of parental care. Here, we used reconstruction of ancestral character states to study the evolution of the two forms of parental care, bubble nesting and mouthbrooding in the fighting fish genus Betta. We also applied a comparative analysis using the phylogenetic generalized least-squares method to test the "safe harbor" hypothesis by evaluating differences between the two forms of parental care in standard length, life-history traits, and three habitat variables. Evolutionary hypotheses were derived from the first molecular phylogeny (nuclear and mitochondrial DNA sequence data; 4448 bp) of this speciose group. Ancestral character state reconstructions of the evolution of the form of parental care in the genus Betta, using the methods of unweighted parsimony and maximum likelihood, are uncertain and further indicate a high rate of evolutionary transitions. Applying different weights for the suspected directionality of changes, based on the consistent phenotypic and behavioral differences found between bubble nesters and mouthbrooders, recurrent origin of mouthbrooding in the genus Betta is favored using parsimony. Our comparative analyses further demonstrate that bubble nesters and mouthbrooders do not have a consistent set of life-history correlates. The form of parental care in Betta is correlated only with offspring size, with mouthbrooders having significantly bigger offspring than bubble nesters, but is not correlated with egg volume, clutch size, and broodcare duration, nor with any of the three habitat variables tested. Our results thus challenge the general predictions of the "safe harbor" hypothesis for the evolution of alternative brood care forms in the fighting fish genus Betta.